In this work, physical models of neoclassical tearing modes （NTMs） including bootstrap current and multiple modulated electron cyclotron current drive model are applied. Based on the specific physical problems durin...In this work, physical models of neoclassical tearing modes （NTMs） including bootstrap current and multiple modulated electron cyclotron current drive model are applied. Based on the specific physical problems during the suppression of NTMs by driven current, this work compares the efficiency of continuous and modulated driven currents, and simulates the physical processes of multiple modulated driven currents on suppressing rotating magnetic island. It is found that when island rotates along the poloidal direction, the suppression ability of continuous driven current can be massively reduced due to current deposition outside the island separatrix and reverse deposition direction at the X point, which can be avoided by current drive modulation. Multiple current drive has a better suppressing effect than single current drive. This work gives realistic numerical simulations by optimizing the model and parameters based on the experiments, which could provide references for successful suppression of NTMs in future advanced tokamak such as international thermonuclear experimental reactor.展开更多
Sample size justification is a very crucial part in the design of clinical trials. In this paper, the authors derive a new formula to calculate the sample size for a binary outcome given one of the three popular indic...Sample size justification is a very crucial part in the design of clinical trials. In this paper, the authors derive a new formula to calculate the sample size for a binary outcome given one of the three popular indices of risk difference.The sample size based on the absolute difference is the fundamental one, which can be easily used to derive sample size given the risk ratio or OR.展开更多
The stabilizing mechanism of toroidal rotation on the tearing mode is studied using the 3 D toroidal resistive magnetohydrodynamic code M3 D.It is found that the dominating mechanism,either the centrifugal effect or t...The stabilizing mechanism of toroidal rotation on the tearing mode is studied using the 3 D toroidal resistive magnetohydrodynamic code M3 D.It is found that the dominating mechanism,either the centrifugal effect or the Coriolis effect, depends on the specific pressure β and rotation frequency Ω.On the premise that Ω is sufficiently large, when β is greater than a critical value,the effect of the centrifugal force is dominant, and the stabilizing effect mainly comes from the modification of equilibrium induced by the centrifugal force;when β is less than a critical value,the stabilizing effect from the Coriolis force overcomes that from the centrifugal force.However,if Ω is small, then the effect of equilibrium modification due to the centrifugal force is not significant even if β is large.Finally, the results showed that toroidal rotation shear enhances the stabilizing effect.展开更多
Incentivised by breakthroughs and data generated by the high-throughput sequencing technology,this paper proposes a distance-based framework to fulfil the emerging needs in elucidating insights from the high-dimension...Incentivised by breakthroughs and data generated by the high-throughput sequencing technology,this paper proposes a distance-based framework to fulfil the emerging needs in elucidating insights from the high-dimensional microbiome data in psychiatric studies.By shifting focus from traditional methods that focus on the observations from each subject to the between-subject attributes that aggregate two or more subjects’entire feature vectors,the described approach revolutionises the conventional prescription for high-dimensional observations via microbiome diversity.To this end,we enrich the classical generalised linear models to articulate the multivariable regression relationship between distance-based variables.We also discuss a robust and computationally feasible semiparametric inference technique.Benefitting from the latest advances in the semiparametric efficiency theory for such attributes,the proposed estimators enjoy robustness and good asymptotic properties that guarantee sensitivity in detecting signals between clinical outcomes and microbiome diversity.It offers a readily implementable and easily interpretable solution for deciphering the gut–brain axis in mental health research.展开更多
SUMMARY In many statistical applications,composite variables are constructed to reduce the number of variables and improve the performances of statistical analyses of these variables,especially when some of the variab...SUMMARY In many statistical applications,composite variables are constructed to reduce the number of variables and improve the performances of statistical analyses of these variables,especially when some of the variables are highly correlated.Principal component analysis(PCA)and factor analysis(FA)are generally used for such purposes.If the variables are used as explanatory or independent variables in linear regression analysis,partial least squares(PLS)regression is a better alternative.Unlike PCA and FA,PLS creates composite variables by also taking into account the response,or dependent variable,so that they have higher correlations with the response than composites from their PCA and FA counterparts.In this report,we provide an introduction to this useful approach and illustrate it with data from a real study.展开更多
基金supported by National Natural Science Foundation of China(Grand Nos.11605021,11375039 and 11275034)Natural Science Foundation of Liaoning Province(Grand No.201601074)supported by'the Fundamental Research Funds for the Central Universities'(Grand Nos.3132016128 and 3132014328)
文摘In this work, physical models of neoclassical tearing modes （NTMs） including bootstrap current and multiple modulated electron cyclotron current drive model are applied. Based on the specific physical problems during the suppression of NTMs by driven current, this work compares the efficiency of continuous and modulated driven currents, and simulates the physical processes of multiple modulated driven currents on suppressing rotating magnetic island. It is found that when island rotates along the poloidal direction, the suppression ability of continuous driven current can be massively reduced due to current deposition outside the island separatrix and reverse deposition direction at the X point, which can be avoided by current drive modulation. Multiple current drive has a better suppressing effect than single current drive. This work gives realistic numerical simulations by optimizing the model and parameters based on the experiments, which could provide references for successful suppression of NTMs in future advanced tokamak such as international thermonuclear experimental reactor.
文摘Sample size justification is a very crucial part in the design of clinical trials. In this paper, the authors derive a new formula to calculate the sample size for a binary outcome given one of the three popular indices of risk difference.The sample size based on the absolute difference is the fundamental one, which can be easily used to derive sample size given the risk ratio or OR.
基金supported by National Natural Science Foundation of China(Grant Nos.11975068 and 11605021)the National Key R&D Program of China(Grant No.2017YFE0301900)+2 种基金the Key Research Program of Frontier Science of Chinese Academy of Sciences(Grant No.QYZDJSSW-SYS016)the Youth Innovation Promotion Association of CASthe Fundamental Research Funds for the Central Universities(Grant No.DUT18ZD101)。
文摘The stabilizing mechanism of toroidal rotation on the tearing mode is studied using the 3 D toroidal resistive magnetohydrodynamic code M3 D.It is found that the dominating mechanism,either the centrifugal effect or the Coriolis effect, depends on the specific pressure β and rotation frequency Ω.On the premise that Ω is sufficiently large, when β is greater than a critical value,the effect of the centrifugal force is dominant, and the stabilizing effect mainly comes from the modification of equilibrium induced by the centrifugal force;when β is less than a critical value,the stabilizing effect from the Coriolis force overcomes that from the centrifugal force.However,if Ω is small, then the effect of equilibrium modification due to the centrifugal force is not significant even if β is large.Finally, the results showed that toroidal rotation shear enhances the stabilizing effect.
文摘Incentivised by breakthroughs and data generated by the high-throughput sequencing technology,this paper proposes a distance-based framework to fulfil the emerging needs in elucidating insights from the high-dimensional microbiome data in psychiatric studies.By shifting focus from traditional methods that focus on the observations from each subject to the between-subject attributes that aggregate two or more subjects’entire feature vectors,the described approach revolutionises the conventional prescription for high-dimensional observations via microbiome diversity.To this end,we enrich the classical generalised linear models to articulate the multivariable regression relationship between distance-based variables.We also discuss a robust and computationally feasible semiparametric inference technique.Benefitting from the latest advances in the semiparametric efficiency theory for such attributes,the proposed estimators enjoy robustness and good asymptotic properties that guarantee sensitivity in detecting signals between clinical outcomes and microbiome diversity.It offers a readily implementable and easily interpretable solution for deciphering the gut–brain axis in mental health research.
基金This study was funded by National Institutes of Health(UL1TR001442).
文摘SUMMARY In many statistical applications,composite variables are constructed to reduce the number of variables and improve the performances of statistical analyses of these variables,especially when some of the variables are highly correlated.Principal component analysis(PCA)and factor analysis(FA)are generally used for such purposes.If the variables are used as explanatory or independent variables in linear regression analysis,partial least squares(PLS)regression is a better alternative.Unlike PCA and FA,PLS creates composite variables by also taking into account the response,or dependent variable,so that they have higher correlations with the response than composites from their PCA and FA counterparts.In this report,we provide an introduction to this useful approach and illustrate it with data from a real study.
