Geomagnetic observatory data are crucial for all branches of geophysics because they can contribute to earthquake research by detecting anomalies in the Earth’s magnetic field.Recently,data records from the Misallat(...Geomagnetic observatory data are crucial for all branches of geophysics because they can contribute to earthquake research by detecting anomalies in the Earth’s magnetic field.Recently,data records from the Misallat(MLT)and Abu Simbel(ABS)Egyptian geomagnetic observatories were processed and found to be of good quality.In this study,Egyptian observatory data were tested during both quiet and disturbed events and compared with data from INTERMAGNET observatories worldwide at different latitudes and within a narrow range of longitudes in both hemispheres.This study investigated the relationships between magnetic field components from Egyptian observatories and those from INTERMAGNET observatories using graphical representations of the X components;Pearson’s correlation for the X,Y,Z,and F components;cross-correlation for the X component;and wavelet coherence for the F component.The results of this study showed a high correlation between Egyptian observatories and all utilized INTERMAGNET stations,except those located at high latitudes,during both quiet and disturbed events.Additionally,the study confirmed the observed consistency between Egyptian observatories and selected INTERMAGNET stations.Therefore,Egyptian observatories can feasibly fill the gap in the Middle East and North Africa.展开更多
Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign cur...Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign currencies each with a different strike price in the payoff function. We carry out a comparative performance analysis of different stochastic volatility (SV), stochastic correlation (SC), and stochastic exchange rate (SER) models to determine the best combination of these models for Monte Carlo (MC) simulation pricing. In addition, we test the performance of all model variants with constant correlation as a benchmark. We find that a combination of GARCH-Jump SV, Weibull SC, and Ornstein Uhlenbeck (OU) SER performs best. In addition, we analyze different discretization schemes and their results. In our simulations, the Milstein scheme yields the best balance between execution times and lower standard deviations of price estimates. Furthermore, we find that incorporating mean reversion into stochastic correlation and stochastic FX rate modeling is beneficial for MC simulation pricing. We improve the accuracy of our simulations by implementing antithetic variates variance reduction. Finally, we derive the correlation risk parameters Cora and Gora in our framework so that correlation hedging of quanto options can be performed.展开更多
Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the m...Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the measurements. At MF3E, moderate variability was observed in apparent electrical conductivity shallow (ECas), slope, and ECa ratio measurements, with coefficients of variation ranging from 20% to 27%. In contrast, MF11S exhibited higher variability, particularly in ECas and ECad (deep) measurements, which exceeded 30% in their coefficient of variation values, indicating significant differences in soil composition and moisture content. Correlation analysis revealed strong positive relationships between the near-infrared-to-red ratio and red reflectance (r = 0.897***) soil values at MF3E. MF11S demonstrated a strong negative correlation between ECas and ECad readings with the x-coordinate (r ***). Scatter plots and fitted models illustrated the complexity of relationships, with many showing nonlinear trends. These findings emphasize the need for continuous monitoring and advanced modeling to understand the dynamic nature of soil properties and their implications for agricultural practices. Future research should explore the underlying mechanisms driving variability in the soil characteristics to enhance soil management strategies at the study sites.展开更多
Background: The use of assisted reproductive technique (ART) is becoming more common in infertility. During ART most patients undergo ovarian stimulation. In this study we study the correlation between ovarian reserve...Background: The use of assisted reproductive technique (ART) is becoming more common in infertility. During ART most patients undergo ovarian stimulation. In this study we study the correlation between ovarian reserve markers: Anti-Mullerian hormone (AMH) and antral follicle count (AFC), and the response to ovarian stimulation at in vitro fertilization (IVF) centres in Douala Cameroon. Methods: This was a hospital based cross-sectional sectional analytic study carried out over a period of 3 years, 4 months at Clinique de l’Aéroport, Clinique Odyssée and Clinique Urogyn. Inclusion criteria were: Female partners of infertile couples undergoing ovarian stimulation for an in vitro fertilization cycle, patients who had both ovaries and had done either AMH, AFC or both before ovarian stimulation. Patients were divided into three groups based on the number of oocytes retrieved: low ovarian response for ≤3 oocytes, normal ovarian response for 4 - 15 oocytes and high ovarian response for >15 oocytes. Data obtained was analyzed by SPSS version 25.0. Results: The ages of participants ranged from 20 - 4 7 years, with a mean age of 34.11 ± 5.11 years. Most of them had secondary infertility (57.9%). The GnRH antagonist protocol was mainly used, and ovulation was triggered using HCG predominantly. On Multivariate analysis, age and history of PCOS were significantly associated with ovarian response in the low and high ovarian response groups, respectively. Conclusion: AMH has a better predictive value than AFC, however, it is less sensitive but more specific than AFC.展开更多
BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression result...BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1.展开更多
Bone marrow edema syndrome (BMES), is a rare and self-limiting condition characterized by localized bone pain and transient marrow edema visible on MRI. BMES has been increasingly associated with specific cutaneous ma...Bone marrow edema syndrome (BMES), is a rare and self-limiting condition characterized by localized bone pain and transient marrow edema visible on MRI. BMES has been increasingly associated with specific cutaneous manifestations that may hold diagnostic and prognostic significance. Patients with BMES have reported localized erythema, dermal thickening, and induration overlying the affected joints, which are hypothesized to reflect microvascular compromise and inflammatory processes within the bone and adjacent soft tissues. Dermatologic signs are likely linked to regional hyperemia, venous stasis, and cytokine-mediated inflammation, paralleling the pathophysiological mechanisms underlying intraosseous edema. Elevated intraosseous pressure in BMES may disrupt local perfusion, resulting in ischemia-reperfusion injury and subsequent vascular leakage, which manifests in visible cutaneous changes. Pro-inflammatory mediators, such as interleukin-1β and vascular endothelial growth factor (VEGF), central to BMES pathogenesis, may exacerbate endothelial activation, and dermal involvement. Histopathologic studies of affected skin have revealed perivascular lymphocytic infiltration and increased dermal vascularity, further supporting the theory of a shared ischemic and inflammatory pathway between bone and skin. Although MRI remains the gold standard for BMES diagnosis, recognition of these cutaneous manifestations could expedite orthopedic referral and intervention, especially in cases where imaging is delayed or symptoms are ambiguous. Current treatment options, including bisphosphonates, prostacyclin analogs, and offloading of weight bearing, may benefit from integration with dermatologic strategies to alleviate localized cutaneous symptoms and improve patient comfort. Evaluating the molecular and vascular links between BMES and its cutaneous manifestations provides an opportunity to refine diagnostic protocols and therapeutic approaches, offering a comprehensive understanding of the systemic interplay between dermal and skeletal pathophysiology, and optimizing clinical outcomes for patients affected by BMES.展开更多
Dear Editor,Recently,Liang et al.(2024)conducted comprehensive genome resequencing and metabolomic analyses of 299 representative accessions from extant citrus species,offering an extensive overview of genetic diversi...Dear Editor,Recently,Liang et al.(2024)conducted comprehensive genome resequencing and metabolomic analyses of 299 representative accessions from extant citrus species,offering an extensive overview of genetic diversity and metabolic profiles across citrus populations.Their study included a correlation analysis that assessed the relationship between metabolite content and bioactivities,resulting in the selection of the top 100 annotated metabolites exhibiting the highest correlation coefficients(Pearson’s r)across various chemical assays,cell lines,and CYP450 enzymes(Liang et al.,2024).展开更多
To study the main aroma components of Phalaenopsis orchid and their relationship with colors,10 fragrant cultivars with different colors,like pink,rose,yellow,and purple,were used as samples in this experiment.Headspa...To study the main aroma components of Phalaenopsis orchid and their relationship with colors,10 fragrant cultivars with different colors,like pink,rose,yellow,and purple,were used as samples in this experiment.Headspace-gas chromatography-mass spectrometry was used to determine the main components of floral fragrance and analyze the correlation between floral color and fragrance.The results showed that the main aroma components of the 10 fragrant cultivars of Phalaenopsis were alcohols,alkenes,esters,and benzene ring compounds,and the main aroma components of different cultivars were diverse.The main aroma components of yellow fragrant flowers were esters,alcohols,and alkenes.The purple and pink series were alcohols and phenyl rings.There was a certain correlation between flower color and floral fragrance.There was a significant positive correlation between esters and flower color C^(*)value,and a significant negative correlation between alkenes and flower color h value.There was a significant negative correlation between alcohol and flower color C^(*)value,and a significant positive correlation between alcohol and L^(*)value.The content of benzene compounds was negatively correlated with L^(*)and positively correlated with h value.This may be related to the synthesizing of anthocyanins and benzene ring compounds through the phenylpropanoid metabolic pathway.In this paper,the correlation between Phalaenopsis floral color and fragrance was studied,and the synthetic pathway of floral color and fragrance components was analyzed.The proposed method and research data can provide a theoretical basis for floral color breeding and fragrance synthesis.展开更多
BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine t...BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine the association of resilience with coping styles and quality of life in patients with malignancies.METHODS This study included patients with malignant tumors who were hospitalized at Fuyang Hospital Affiliated to Anhui Medical University from March 2022 to March 2024.The Connor-Davidson Resilience Scale,Medical Coping Modes Questionnaire,Social Support Rating Scale,and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 were utilized to assess patients’resilience,coping styles,social support,and quality of life,respectively.Pearson correlation analysis was conducted to assess the correlations.RESULTS A total of 175 patients with malignant tumors demonstrated no marked difference in terms of age,education level,employment status,monthly household income,and disease staging(P<0.05).Further,patients with malignancies demonstrated scores of 17.49±1.20,17.27±1.46,and 11.19±1.29 points in terms of coping styles in confrontation,avoidance,and resignation dimensions,respectively.Subjective support,objective support,and support utilization scores in terms of social support were 10.67±1.80,11.26±2.08,and 9.24±1.14 points,respectively.The total resilience score and tenacity,self-improvement,and optimism dimension scores were positively correlatedwith the confrontation coping style score,whereas the total resilience score and tenacity and self-improvementscores were negatively associated with avoidance and resignation coping style scores(P<0.05).The total resiliencescore and the tenacity dimension score were positively associated with physical,role,cognitive,emotional,andsocial functions,as well as global health status(P<0.05),and were inversely related to fatigue,insomnia,andeconomic difficulties(P<0.05).CONCLUSIONThe resilience of patients with malignancies is positively associated with the confrontation dimension in the copingstyle,the total and various social support domain scores,and the overall quality of life.Clinical medical staff needto pay attention to the effect of medical coping styles and social support on the resilience level of patients withmalignancies to further improve their quality of life.展开更多
Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with ot...Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with other elements, and the environment. It is subsequently composed of many components, only some of which take part in the couplings. In this paper we present a framework to detect the component correlation pattern. Firstly, the interested trajectories are decomposed into components by using decomposing methods such as the Fourier expansion and the Wavelet transformation. Secondly, the cross-correlations between the components are calculated, resulting into a component cross-correlation matrix(network).Finally, the dominant structure in the network is identified to characterize the coupling pattern in the system. Several deterministic dynamical models turn out to be characterized with rich structures such as the clustering of the components. The pattern of correlation between respiratory(RESP) and ECG signals is composed of five sub-clusters that are mainly formed by the components in ECG signal. Interestingly, only 7 components from RESP(scattered in four sub-clusters) take part in the realization of coupling between the two signals.展开更多
Video snapshot compressive imaging(Video SCI) modulates scenes using various encoding masks and captures compressed measurements with a low-speed camera during a single exposure. Subsequently, reconstruction algorithm...Video snapshot compressive imaging(Video SCI) modulates scenes using various encoding masks and captures compressed measurements with a low-speed camera during a single exposure. Subsequently, reconstruction algorithms restore image sequences of dynamic scenes, offering advantages such as reduced bandwidth and storage space requirements. The temporal correlation in video data is crucial for Video SCI, as it leverages the temporal relationships among frames to enhance the efficiency and quality of reconstruction algorithms, particularly for fast-moving objects.This paper discretizes video frames to create image datasets with the same data volume but differing temporal correlations. We utilized the state-of-the-art(SOTA) reconstruction framework, EfficientSCI++, to train various compressed reconstruction models with these differing temporal correlations. Evaluating the reconstruction results from these models, our simulation experiments confirm that a reduction in temporal correlation leads to decreased reconstruction accuracy. Additionally, we simulated the reconstruction outcomes of datasets devoid of temporal correlation, illustrating that models trained on non-temporal data affect the temporal feature extraction capabilities of transformers, resulting in negligible impacts on the evaluation of reconstruction results for non-temporal correlation test datasets.展开更多
For non-stationary complex dynamic systems,a standardized algorithm is developed to compute time correlation functions,addressing the limitations of traditional methods reliant on the stationary assumption.The propose...For non-stationary complex dynamic systems,a standardized algorithm is developed to compute time correlation functions,addressing the limitations of traditional methods reliant on the stationary assumption.The proposed algorithm integrates two-point and multi-point time correlation functions into a unified framework.Further,it is verified by a practical application in complex financial systems,demonstrating its potential in various complex dynamic systems.展开更多
Stimulated by a keen interest in possible collective behavior in high-energy proton-proton and protonnucleus collisions,we study two-particle angular correlations in pseudorapidity and azimuthal differences in simulat...Stimulated by a keen interest in possible collective behavior in high-energy proton-proton and protonnucleus collisions,we study two-particle angular correlations in pseudorapidity and azimuthal differences in simulated p+p interactions using the Pythia 8 event generator.Multi-parton interactions and color connection are included in these simulations,which have been perceived to produce collectivity in final-state particles.Meanwhile,contributions from genuine few-body nonflow correlations,not of collective flow behavior,are known to be severe in these small-system collisions.We present our Pythia correlation studies pedagogically and report azimuthal harmonic anisotropies analyzed using several methods.We observe anisotropies in these Pythia simulated events qualitatively and semi-quantitatively,similar to experimental data.Our findings highlight the delicate nature of azimuthal anisotropies in small-system collisions and provide a benchmark that can aid in improving data analysis and interpreting experimental measurements in small-system collisions.展开更多
This study aims to understand the current status of fear of disease progression(FoP)in patients with coronary heart disease(CHD)following percutaneous coronary intervention(PCI),and to explore the relationship between...This study aims to understand the current status of fear of disease progression(FoP)in patients with coronary heart disease(CHD)following percutaneous coronary intervention(PCI),and to explore the relationship between FoP levels,perceived control,and medical coping strategies in these patients.A total of 360 CHD patients who underwent PCI at Xijing Hospital in Shaanxi Province between June and November 2024 were selected using a convenience sampling method.Surveys included a general information questionnaire,the Fear of Progression Questionnaire-Short Form(FoP-Q-SF),the revised Control Attitudes Scale(CAS-R),and the Medical Coping Modes Questionnaire(MCMQ).Pearson correlation analysis was used to examine the relationships between disease perception,positive coping strategies,and FoP.A total of 360 patients completed the study.The average score for FoP in patients with CHD after PCI was 31.64±4.61.FoP was negatively correlated with perceived control(r=-0.106,P<0.01)and medical coping(r=-0.194,P<0.01).Multivariate regression analysis showed that the type of intervention,family history of CHD,smoking status,perceived control,and total medical coping score were significant factors influencing FoP(P<0.01).Enhancing perceived control and identifying positive coping strategies can improve FoP levels in patients with CHD after PCI.Therefore,clinicians should focus on perceived control and medical coping levels in patients and develop targeted interventions to alleviate negative emotions related to FoP.展开更多
Objective:This study aimed to determine the correlation between the incidence of acute mountain sickness(AMS)and the body constitution of Tibetan medicine and other relevant factors to provide a reference for the pred...Objective:This study aimed to determine the correlation between the incidence of acute mountain sickness(AMS)and the body constitution of Tibetan medicine and other relevant factors to provide a reference for the prediction and prevention of AMS.Methods:A caseecontrol study was conducted to recruit participants who experienced or did not experience AMS after entering a plateau.The data was collected through online questionnaires for convenient sampling.Demographic characteristics,body constitution,and related states or behaviors were investigated before and after entering the plateau.The participants were divided into case and control groups based on the incidence of AMS.The distributions of relevant factors were compared.Binary logistic regression analysis was used to screen for risk and protective factors.Results:There were 167 participants who completed the questionnaire.A total of 54 cases were excluded,and 113 participants were included,including 52 in the case group and 61 in the control group.In the case group,37,13,and 2 patients had mild,moderate,and severe AMS,respectively.In terms of the Tibetan medicine constitution,the case group had the highest proportion of Bad-rlung(25.0%)and Rlung types(21.2%),whereas the control group had the highest proportion of Bad-rlung(29.5%)and Mkhrisbad types(24.6%).There was no significant difference in the distribution of the constitutional types between the two groups.Insomnia or insufficient sleep within the week prior to entering the plateau and fatigue after arrival were risk factors for AMS,with odds ratios(OR)and 95%confidence intervals(CI)of 5.012(1.871e13.426)and 3.387(1.393e8.236),respectively.A history of short-term plateau travel is a protective factor for AMS(OR:0.32,95%CI:0.129 to 0.792).Conclusion:Insomnia or lack of sleep before ascending to a plateau and fatigue after arrival are risk factors for AMS.The Rlung constitution might be related to the incidence of AMS;however,this still needs to be verified in large-sample observational studies.The risk factors identified in this study can provide a reference for the prevention practice and research of AMS.展开更多
Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the ...Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the probability of catastrophic behavior in case of accidents.Equilibrium damage accumulation in some cases leads to a falling part(called a postcritical stage)on the material’s stress-strain curve.It must be taken into account to assess the strength and deformation limits of composite structures.Digital image correlation method,acoustic emission(AE)signals recording,and optical microscopy were used in this paper to study the deformation and failure processes of an orthogonal-layup composite during tension in various directions to orthotropy axes.An elastic-plastic deformation model was proposed for the composite in a plane stress condition.The evolution of strain fields and neck formation were analyzed.The staging of the postcritical deformation process was described.AE signals obtained during tests were studied;characteristic damage types of a material were defined.The rationality and necessity of polymer composites’postcritical deformation stage taken into account in refined strength analysis of structures were concluded.展开更多
Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies ha...Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping SGDCs.Here,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical forest.For this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural Reserve.We also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest plots.We found that speciesα-diversity was negatively correlated with geneticα-diversity.Canopy structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-diversity.These contrasting effects contributed to the formation of a negativeα-SGDC.Further,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target species.Speciesβ-diversity,in contrast,was positively correlated with geneticβ-diversity.Differences in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-SGDC.Our study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs.展开更多
AIM:To assess the repeatability,interocular correlation,and agreement of quantitative swept-source optical coherence tomography angiography(OCTA)optic nerve head(ONH)parameters in healthy subjects.METHODS:Thir ty-thre...AIM:To assess the repeatability,interocular correlation,and agreement of quantitative swept-source optical coherence tomography angiography(OCTA)optic nerve head(ONH)parameters in healthy subjects.METHODS:Thir ty-three healthy subjects were enrolled.The ONH of both eyes were imaged four times by a swept-source-OCTA using a 3 mm×3 mm scanning protocol.Images of the radial peripapillary capillary were analyzed by a customized Matlab program,and the vessel density,fractal dimension,and vessel diameter index were measured.The repeatability of the four scans was determined by the intraclass correlation coefficient(ICC).The most well-centered optic disc from the four repeated scans was then selected for the interocular correlation and agreement analysis using the Pearson correlation coefficient,ICC and Bland-Altman plots.RESULTS:All swept-source-OCTA ONH parameters exhibited certain repeatability,with ICC>0.760 and coefficient of variation(CoV)≤7.301%.The obvious interocular correlation was observed for papillary vessel density(ICC=0.857),vessel diameter index(ICC=0.857)and fractal dimension(ICC=0.906),while circumpapillary vessel density exhibited moderate interocular correlation(ICC=0.687).Bland-Altman plots revealed an agreement range of-5.26%to 6.21%for circumpapillary vessel density.CONCLUSION:OCTA ONH parameters demonstrate good repeatability in healthy subjects.The interocular correlations of papillary vessel density,fractal dimension and vessel diameter index are high,but the correlation for circumpapillary vessel density is moderate.展开更多
Low Earth Orbit(LEO)multibeam satellites will be widely used in the next generation of satellite communication systems,whose inter-beam interference will inevitably limit the performance of the whole system.Nonlinear ...Low Earth Orbit(LEO)multibeam satellites will be widely used in the next generation of satellite communication systems,whose inter-beam interference will inevitably limit the performance of the whole system.Nonlinear precoding such as Tomlinson-Harashima precoding(THP)algorithm has been proved to be a promising technology to solve this problem,which has smaller noise amplification effect compared with linear precoding.However,the similarity of different user channels(defined as channel correlation)will degrade the performance of THP algorithm.In this paper,we qualitatively analyze the inter-beam interference in the whole process of LEO satellite over a specific coverage area,and the impact of channel correlation on Signal-to-Noise Ratio(SNR)of receivers when THP is applied.One user grouping algorithm is proposed based on the analysis of channel correlation,which could decrease the number of users with high channel correlation in each precoding group,thus improve the performance of THP.Furthermore,our algorithm is designed under the premise of co-frequency deployment and orthogonal frequency division multiplexing(OFDM),which leads to more users under severe inter-beam interference compared to the existing research on geostationary orbit satellites broadcasting systems.Simulation results show that the proposed user grouping algorithm possesses higher channel capacity and better bit error rate(BER)performance in high SNR conditions relative to existing works.展开更多
With the improvement of equipment reliability,human factors have become the most uncertain part in the system.The standardized Plant Analysis of Risk-Human Reliability Analysis(SPAR-H)method is a reliable method in th...With the improvement of equipment reliability,human factors have become the most uncertain part in the system.The standardized Plant Analysis of Risk-Human Reliability Analysis(SPAR-H)method is a reliable method in the field of human reliability analysis(HRA)to evaluate human reliability and assess risk in large complex systems.However,the classical SPAR-H method does not consider the dependencies among performance shaping factors(PSFs),whichmay cause overestimation or underestimation of the risk of the actual situation.To address this issue,this paper proposes a new method to deal with the dependencies among PSFs in SPAR-H based on the Pearson correlation coefficient.First,the dependence between every two PSFs is measured by the Pearson correlation coefficient.Second,the weights of the PSFs are obtained by considering the total dependence degree.Finally,PSFs’multipliers are modified based on the weights of corresponding PSFs,and then used in the calculating of human error probability(HEP).A case study is used to illustrate the procedure and effectiveness of the proposed method.展开更多
文摘Geomagnetic observatory data are crucial for all branches of geophysics because they can contribute to earthquake research by detecting anomalies in the Earth’s magnetic field.Recently,data records from the Misallat(MLT)and Abu Simbel(ABS)Egyptian geomagnetic observatories were processed and found to be of good quality.In this study,Egyptian observatory data were tested during both quiet and disturbed events and compared with data from INTERMAGNET observatories worldwide at different latitudes and within a narrow range of longitudes in both hemispheres.This study investigated the relationships between magnetic field components from Egyptian observatories and those from INTERMAGNET observatories using graphical representations of the X components;Pearson’s correlation for the X,Y,Z,and F components;cross-correlation for the X component;and wavelet coherence for the F component.The results of this study showed a high correlation between Egyptian observatories and all utilized INTERMAGNET stations,except those located at high latitudes,during both quiet and disturbed events.Additionally,the study confirmed the observed consistency between Egyptian observatories and selected INTERMAGNET stations.Therefore,Egyptian observatories can feasibly fill the gap in the Middle East and North Africa.
文摘Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign currencies each with a different strike price in the payoff function. We carry out a comparative performance analysis of different stochastic volatility (SV), stochastic correlation (SC), and stochastic exchange rate (SER) models to determine the best combination of these models for Monte Carlo (MC) simulation pricing. In addition, we test the performance of all model variants with constant correlation as a benchmark. We find that a combination of GARCH-Jump SV, Weibull SC, and Ornstein Uhlenbeck (OU) SER performs best. In addition, we analyze different discretization schemes and their results. In our simulations, the Milstein scheme yields the best balance between execution times and lower standard deviations of price estimates. Furthermore, we find that incorporating mean reversion into stochastic correlation and stochastic FX rate modeling is beneficial for MC simulation pricing. We improve the accuracy of our simulations by implementing antithetic variates variance reduction. Finally, we derive the correlation risk parameters Cora and Gora in our framework so that correlation hedging of quanto options can be performed.
文摘Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the measurements. At MF3E, moderate variability was observed in apparent electrical conductivity shallow (ECas), slope, and ECa ratio measurements, with coefficients of variation ranging from 20% to 27%. In contrast, MF11S exhibited higher variability, particularly in ECas and ECad (deep) measurements, which exceeded 30% in their coefficient of variation values, indicating significant differences in soil composition and moisture content. Correlation analysis revealed strong positive relationships between the near-infrared-to-red ratio and red reflectance (r = 0.897***) soil values at MF3E. MF11S demonstrated a strong negative correlation between ECas and ECad readings with the x-coordinate (r ***). Scatter plots and fitted models illustrated the complexity of relationships, with many showing nonlinear trends. These findings emphasize the need for continuous monitoring and advanced modeling to understand the dynamic nature of soil properties and their implications for agricultural practices. Future research should explore the underlying mechanisms driving variability in the soil characteristics to enhance soil management strategies at the study sites.
文摘Background: The use of assisted reproductive technique (ART) is becoming more common in infertility. During ART most patients undergo ovarian stimulation. In this study we study the correlation between ovarian reserve markers: Anti-Mullerian hormone (AMH) and antral follicle count (AFC), and the response to ovarian stimulation at in vitro fertilization (IVF) centres in Douala Cameroon. Methods: This was a hospital based cross-sectional sectional analytic study carried out over a period of 3 years, 4 months at Clinique de l’Aéroport, Clinique Odyssée and Clinique Urogyn. Inclusion criteria were: Female partners of infertile couples undergoing ovarian stimulation for an in vitro fertilization cycle, patients who had both ovaries and had done either AMH, AFC or both before ovarian stimulation. Patients were divided into three groups based on the number of oocytes retrieved: low ovarian response for ≤3 oocytes, normal ovarian response for 4 - 15 oocytes and high ovarian response for >15 oocytes. Data obtained was analyzed by SPSS version 25.0. Results: The ages of participants ranged from 20 - 4 7 years, with a mean age of 34.11 ± 5.11 years. Most of them had secondary infertility (57.9%). The GnRH antagonist protocol was mainly used, and ovulation was triggered using HCG predominantly. On Multivariate analysis, age and history of PCOS were significantly associated with ovarian response in the low and high ovarian response groups, respectively. Conclusion: AMH has a better predictive value than AFC, however, it is less sensitive but more specific than AFC.
基金Supported by Innovative Practice Platform for Undergraduate Students,School of Public Health Xiamen University,No.2021001.
文摘BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1.
文摘Bone marrow edema syndrome (BMES), is a rare and self-limiting condition characterized by localized bone pain and transient marrow edema visible on MRI. BMES has been increasingly associated with specific cutaneous manifestations that may hold diagnostic and prognostic significance. Patients with BMES have reported localized erythema, dermal thickening, and induration overlying the affected joints, which are hypothesized to reflect microvascular compromise and inflammatory processes within the bone and adjacent soft tissues. Dermatologic signs are likely linked to regional hyperemia, venous stasis, and cytokine-mediated inflammation, paralleling the pathophysiological mechanisms underlying intraosseous edema. Elevated intraosseous pressure in BMES may disrupt local perfusion, resulting in ischemia-reperfusion injury and subsequent vascular leakage, which manifests in visible cutaneous changes. Pro-inflammatory mediators, such as interleukin-1β and vascular endothelial growth factor (VEGF), central to BMES pathogenesis, may exacerbate endothelial activation, and dermal involvement. Histopathologic studies of affected skin have revealed perivascular lymphocytic infiltration and increased dermal vascularity, further supporting the theory of a shared ischemic and inflammatory pathway between bone and skin. Although MRI remains the gold standard for BMES diagnosis, recognition of these cutaneous manifestations could expedite orthopedic referral and intervention, especially in cases where imaging is delayed or symptoms are ambiguous. Current treatment options, including bisphosphonates, prostacyclin analogs, and offloading of weight bearing, may benefit from integration with dermatologic strategies to alleviate localized cutaneous symptoms and improve patient comfort. Evaluating the molecular and vascular links between BMES and its cutaneous manifestations provides an opportunity to refine diagnostic protocols and therapeutic approaches, offering a comprehensive understanding of the systemic interplay between dermal and skeletal pathophysiology, and optimizing clinical outcomes for patients affected by BMES.
文摘Dear Editor,Recently,Liang et al.(2024)conducted comprehensive genome resequencing and metabolomic analyses of 299 representative accessions from extant citrus species,offering an extensive overview of genetic diversity and metabolic profiles across citrus populations.Their study included a correlation analysis that assessed the relationship between metabolite content and bioactivities,resulting in the selection of the top 100 annotated metabolites exhibiting the highest correlation coefficients(Pearson’s r)across various chemical assays,cell lines,and CYP450 enzymes(Liang et al.,2024).
基金supported by the Shandong Province Key Research and Development Plan Project(ID Numbers 2024LZGC026 and 2021LZGC019)Shanghai Science and Technology Agriculture Project(ID Number 2020-02-08-00-12-F01463).
文摘To study the main aroma components of Phalaenopsis orchid and their relationship with colors,10 fragrant cultivars with different colors,like pink,rose,yellow,and purple,were used as samples in this experiment.Headspace-gas chromatography-mass spectrometry was used to determine the main components of floral fragrance and analyze the correlation between floral color and fragrance.The results showed that the main aroma components of the 10 fragrant cultivars of Phalaenopsis were alcohols,alkenes,esters,and benzene ring compounds,and the main aroma components of different cultivars were diverse.The main aroma components of yellow fragrant flowers were esters,alcohols,and alkenes.The purple and pink series were alcohols and phenyl rings.There was a certain correlation between flower color and floral fragrance.There was a significant positive correlation between esters and flower color C^(*)value,and a significant negative correlation between alkenes and flower color h value.There was a significant negative correlation between alcohol and flower color C^(*)value,and a significant positive correlation between alcohol and L^(*)value.The content of benzene compounds was negatively correlated with L^(*)and positively correlated with h value.This may be related to the synthesizing of anthocyanins and benzene ring compounds through the phenylpropanoid metabolic pathway.In this paper,the correlation between Phalaenopsis floral color and fragrance was studied,and the synthetic pathway of floral color and fragrance components was analyzed.The proposed method and research data can provide a theoretical basis for floral color breeding and fragrance synthesis.
文摘BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine the association of resilience with coping styles and quality of life in patients with malignancies.METHODS This study included patients with malignant tumors who were hospitalized at Fuyang Hospital Affiliated to Anhui Medical University from March 2022 to March 2024.The Connor-Davidson Resilience Scale,Medical Coping Modes Questionnaire,Social Support Rating Scale,and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 were utilized to assess patients’resilience,coping styles,social support,and quality of life,respectively.Pearson correlation analysis was conducted to assess the correlations.RESULTS A total of 175 patients with malignant tumors demonstrated no marked difference in terms of age,education level,employment status,monthly household income,and disease staging(P<0.05).Further,patients with malignancies demonstrated scores of 17.49±1.20,17.27±1.46,and 11.19±1.29 points in terms of coping styles in confrontation,avoidance,and resignation dimensions,respectively.Subjective support,objective support,and support utilization scores in terms of social support were 10.67±1.80,11.26±2.08,and 9.24±1.14 points,respectively.The total resilience score and tenacity,self-improvement,and optimism dimension scores were positively correlatedwith the confrontation coping style score,whereas the total resilience score and tenacity and self-improvementscores were negatively associated with avoidance and resignation coping style scores(P<0.05).The total resiliencescore and the tenacity dimension score were positively associated with physical,role,cognitive,emotional,andsocial functions,as well as global health status(P<0.05),and were inversely related to fatigue,insomnia,andeconomic difficulties(P<0.05).CONCLUSIONThe resilience of patients with malignancies is positively associated with the confrontation dimension in the copingstyle,the total and various social support domain scores,and the overall quality of life.Clinical medical staff needto pay attention to the effect of medical coping styles and social support on the resilience level of patients withmalignancies to further improve their quality of life.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11875042 and 11505114)the Shanghai Project for Construction of Top Disciplines (Grant No. USST-SYS-01)。
文摘Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with other elements, and the environment. It is subsequently composed of many components, only some of which take part in the couplings. In this paper we present a framework to detect the component correlation pattern. Firstly, the interested trajectories are decomposed into components by using decomposing methods such as the Fourier expansion and the Wavelet transformation. Secondly, the cross-correlations between the components are calculated, resulting into a component cross-correlation matrix(network).Finally, the dominant structure in the network is identified to characterize the coupling pattern in the system. Several deterministic dynamical models turn out to be characterized with rich structures such as the clustering of the components. The pattern of correlation between respiratory(RESP) and ECG signals is composed of five sub-clusters that are mainly formed by the components in ECG signal. Interestingly, only 7 components from RESP(scattered in four sub-clusters) take part in the realization of coupling between the two signals.
基金supported in part by the National Natural Science Foundation of China (No. U23B2011)。
文摘Video snapshot compressive imaging(Video SCI) modulates scenes using various encoding masks and captures compressed measurements with a low-speed camera during a single exposure. Subsequently, reconstruction algorithms restore image sequences of dynamic scenes, offering advantages such as reduced bandwidth and storage space requirements. The temporal correlation in video data is crucial for Video SCI, as it leverages the temporal relationships among frames to enhance the efficiency and quality of reconstruction algorithms, particularly for fast-moving objects.This paper discretizes video frames to create image datasets with the same data volume but differing temporal correlations. We utilized the state-of-the-art(SOTA) reconstruction framework, EfficientSCI++, to train various compressed reconstruction models with these differing temporal correlations. Evaluating the reconstruction results from these models, our simulation experiments confirm that a reduction in temporal correlation leads to decreased reconstruction accuracy. Additionally, we simulated the reconstruction outcomes of datasets devoid of temporal correlation, illustrating that models trained on non-temporal data affect the temporal feature extraction capabilities of transformers, resulting in negligible impacts on the evaluation of reconstruction results for non-temporal correlation test datasets.
基金Project supported by the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZC20231050)the National Natural Science Foundation of China(Grant Nos.12175193 and 11905183)the 13th Five-year plan for Education Science Funding of Guangdong Province(Grant No.2021GXJK349)。
文摘For non-stationary complex dynamic systems,a standardized algorithm is developed to compute time correlation functions,addressing the limitations of traditional methods reliant on the stationary assumption.The proposed algorithm integrates two-point and multi-point time correlation functions into a unified framework.Further,it is verified by a practical application in complex financial systems,demonstrating its potential in various complex dynamic systems.
基金Supported in part by the U.S.Department of Energy(DE-SCo012910)。
文摘Stimulated by a keen interest in possible collective behavior in high-energy proton-proton and protonnucleus collisions,we study two-particle angular correlations in pseudorapidity and azimuthal differences in simulated p+p interactions using the Pythia 8 event generator.Multi-parton interactions and color connection are included in these simulations,which have been perceived to produce collectivity in final-state particles.Meanwhile,contributions from genuine few-body nonflow correlations,not of collective flow behavior,are known to be severe in these small-system collisions.We present our Pythia correlation studies pedagogically and report azimuthal harmonic anisotropies analyzed using several methods.We observe anisotropies in these Pythia simulated events qualitatively and semi-quantitatively,similar to experimental data.Our findings highlight the delicate nature of azimuthal anisotropies in small-system collisions and provide a benchmark that can aid in improving data analysis and interpreting experimental measurements in small-system collisions.
文摘This study aims to understand the current status of fear of disease progression(FoP)in patients with coronary heart disease(CHD)following percutaneous coronary intervention(PCI),and to explore the relationship between FoP levels,perceived control,and medical coping strategies in these patients.A total of 360 CHD patients who underwent PCI at Xijing Hospital in Shaanxi Province between June and November 2024 were selected using a convenience sampling method.Surveys included a general information questionnaire,the Fear of Progression Questionnaire-Short Form(FoP-Q-SF),the revised Control Attitudes Scale(CAS-R),and the Medical Coping Modes Questionnaire(MCMQ).Pearson correlation analysis was used to examine the relationships between disease perception,positive coping strategies,and FoP.A total of 360 patients completed the study.The average score for FoP in patients with CHD after PCI was 31.64±4.61.FoP was negatively correlated with perceived control(r=-0.106,P<0.01)and medical coping(r=-0.194,P<0.01).Multivariate regression analysis showed that the type of intervention,family history of CHD,smoking status,perceived control,and total medical coping score were significant factors influencing FoP(P<0.01).Enhancing perceived control and identifying positive coping strategies can improve FoP levels in patients with CHD after PCI.Therefore,clinicians should focus on perceived control and medical coping levels in patients and develop targeted interventions to alleviate negative emotions related to FoP.
基金funded by the institutional program of China Tibetology Research Center(CTRC20236JS08).
文摘Objective:This study aimed to determine the correlation between the incidence of acute mountain sickness(AMS)and the body constitution of Tibetan medicine and other relevant factors to provide a reference for the prediction and prevention of AMS.Methods:A caseecontrol study was conducted to recruit participants who experienced or did not experience AMS after entering a plateau.The data was collected through online questionnaires for convenient sampling.Demographic characteristics,body constitution,and related states or behaviors were investigated before and after entering the plateau.The participants were divided into case and control groups based on the incidence of AMS.The distributions of relevant factors were compared.Binary logistic regression analysis was used to screen for risk and protective factors.Results:There were 167 participants who completed the questionnaire.A total of 54 cases were excluded,and 113 participants were included,including 52 in the case group and 61 in the control group.In the case group,37,13,and 2 patients had mild,moderate,and severe AMS,respectively.In terms of the Tibetan medicine constitution,the case group had the highest proportion of Bad-rlung(25.0%)and Rlung types(21.2%),whereas the control group had the highest proportion of Bad-rlung(29.5%)and Mkhrisbad types(24.6%).There was no significant difference in the distribution of the constitutional types between the two groups.Insomnia or insufficient sleep within the week prior to entering the plateau and fatigue after arrival were risk factors for AMS,with odds ratios(OR)and 95%confidence intervals(CI)of 5.012(1.871e13.426)and 3.387(1.393e8.236),respectively.A history of short-term plateau travel is a protective factor for AMS(OR:0.32,95%CI:0.129 to 0.792).Conclusion:Insomnia or lack of sleep before ascending to a plateau and fatigue after arrival are risk factors for AMS.The Rlung constitution might be related to the incidence of AMS;however,this still needs to be verified in large-sample observational studies.The risk factors identified in this study can provide a reference for the prevention practice and research of AMS.
基金This work was supported by the Russian Science Foundation(Grant No.22-19-00765)at the Perm National Research Polytechnic University.
文摘Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the probability of catastrophic behavior in case of accidents.Equilibrium damage accumulation in some cases leads to a falling part(called a postcritical stage)on the material’s stress-strain curve.It must be taken into account to assess the strength and deformation limits of composite structures.Digital image correlation method,acoustic emission(AE)signals recording,and optical microscopy were used in this paper to study the deformation and failure processes of an orthogonal-layup composite during tension in various directions to orthotropy axes.An elastic-plastic deformation model was proposed for the composite in a plane stress condition.The evolution of strain fields and neck formation were analyzed.The staging of the postcritical deformation process was described.AE signals obtained during tests were studied;characteristic damage types of a material were defined.The rationality and necessity of polymer composites’postcritical deformation stage taken into account in refined strength analysis of structures were concluded.
基金funded by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB31000000)the Joint Fund of the National Natural Science Foundation of China-Yunnan Province (U1902203)+1 种基金Major Program for Basic Research Project of Yunnan Province (202101BC070002)Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (151C53KYSB20200019)
文摘Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping SGDCs.Here,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical forest.For this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural Reserve.We also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest plots.We found that speciesα-diversity was negatively correlated with geneticα-diversity.Canopy structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-diversity.These contrasting effects contributed to the formation of a negativeα-SGDC.Further,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target species.Speciesβ-diversity,in contrast,was positively correlated with geneticβ-diversity.Differences in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-SGDC.Our study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs.
基金Natural Science Foundation of Guangdong Province(No.2018A0303130306)Shantou Science and Technology Program(No.190917085269835,No.200629165261641).
文摘AIM:To assess the repeatability,interocular correlation,and agreement of quantitative swept-source optical coherence tomography angiography(OCTA)optic nerve head(ONH)parameters in healthy subjects.METHODS:Thir ty-three healthy subjects were enrolled.The ONH of both eyes were imaged four times by a swept-source-OCTA using a 3 mm×3 mm scanning protocol.Images of the radial peripapillary capillary were analyzed by a customized Matlab program,and the vessel density,fractal dimension,and vessel diameter index were measured.The repeatability of the four scans was determined by the intraclass correlation coefficient(ICC).The most well-centered optic disc from the four repeated scans was then selected for the interocular correlation and agreement analysis using the Pearson correlation coefficient,ICC and Bland-Altman plots.RESULTS:All swept-source-OCTA ONH parameters exhibited certain repeatability,with ICC>0.760 and coefficient of variation(CoV)≤7.301%.The obvious interocular correlation was observed for papillary vessel density(ICC=0.857),vessel diameter index(ICC=0.857)and fractal dimension(ICC=0.906),while circumpapillary vessel density exhibited moderate interocular correlation(ICC=0.687).Bland-Altman plots revealed an agreement range of-5.26%to 6.21%for circumpapillary vessel density.CONCLUSION:OCTA ONH parameters demonstrate good repeatability in healthy subjects.The interocular correlations of papillary vessel density,fractal dimension and vessel diameter index are high,but the correlation for circumpapillary vessel density is moderate.
基金supported by the Key R&D Project of the Ministry of Science and Technology of China(2020YFB1808005)。
文摘Low Earth Orbit(LEO)multibeam satellites will be widely used in the next generation of satellite communication systems,whose inter-beam interference will inevitably limit the performance of the whole system.Nonlinear precoding such as Tomlinson-Harashima precoding(THP)algorithm has been proved to be a promising technology to solve this problem,which has smaller noise amplification effect compared with linear precoding.However,the similarity of different user channels(defined as channel correlation)will degrade the performance of THP algorithm.In this paper,we qualitatively analyze the inter-beam interference in the whole process of LEO satellite over a specific coverage area,and the impact of channel correlation on Signal-to-Noise Ratio(SNR)of receivers when THP is applied.One user grouping algorithm is proposed based on the analysis of channel correlation,which could decrease the number of users with high channel correlation in each precoding group,thus improve the performance of THP.Furthermore,our algorithm is designed under the premise of co-frequency deployment and orthogonal frequency division multiplexing(OFDM),which leads to more users under severe inter-beam interference compared to the existing research on geostationary orbit satellites broadcasting systems.Simulation results show that the proposed user grouping algorithm possesses higher channel capacity and better bit error rate(BER)performance in high SNR conditions relative to existing works.
基金Shanghai Rising-Star Program(Grant No.21QA1403400)Shanghai Sailing Program(Grant No.20YF1414800)Shanghai Key Laboratory of Power Station Automation Technology(Grant No.13DZ2273800).
文摘With the improvement of equipment reliability,human factors have become the most uncertain part in the system.The standardized Plant Analysis of Risk-Human Reliability Analysis(SPAR-H)method is a reliable method in the field of human reliability analysis(HRA)to evaluate human reliability and assess risk in large complex systems.However,the classical SPAR-H method does not consider the dependencies among performance shaping factors(PSFs),whichmay cause overestimation or underestimation of the risk of the actual situation.To address this issue,this paper proposes a new method to deal with the dependencies among PSFs in SPAR-H based on the Pearson correlation coefficient.First,the dependence between every two PSFs is measured by the Pearson correlation coefficient.Second,the weights of the PSFs are obtained by considering the total dependence degree.Finally,PSFs’multipliers are modified based on the weights of corresponding PSFs,and then used in the calculating of human error probability(HEP).A case study is used to illustrate the procedure and effectiveness of the proposed method.
