Based on a series of recent papers, a powerful algorithm is reformulated for computing the maximal eigenpair of self-adjoint complex tridiagonal matrices. In parallel, the same problem in a particular case for computi...Based on a series of recent papers, a powerful algorithm is reformulated for computing the maximal eigenpair of self-adjoint complex tridiagonal matrices. In parallel, the same problem in a particular case for computing the sub-maximal eigenpair is also introduced. The key ideas for each critical improvement are explained. To illustrate the present algorithm and compare it with the related algorithms, more than 10 examples are included.展开更多
Objective:The article aims to investigate the relationship of parameters such as airway vicosity resistance (R5) and maximal expiratory flow-volume curve (MEFV) with severity of chronic cough in 3 to 5 years old child...Objective:The article aims to investigate the relationship of parameters such as airway vicosity resistance (R5) and maximal expiratory flow-volume curve (MEFV) with severity of chronic cough in 3 to 5 years old children by impulse oscillometry (IOS) detection when the oscillation frequency is 5Hz.Method: The article chooses eighty children with chronic cough who were diagnosed or treated in our hospital from March 2017 to March 2018 as the research group, and chooses 50 healthy children who had physical examination in our hospital as the control group. Children's asthma control test (C-ACT) is used to assess the disease severity of children. MEFV detection is carried out to the two groups of children to obtain the ratio of forced expiratory volume in one second and forced vital capacity (FEV1/FVC) and the peak expiratory flow (PEF). LsS inductance (X5) is detected by IOS when R5, the resonant frequency (Fres), and the oscillation frequency is 5Hz. The relationship of ACT score with MEFV and IOS indicators is analyzed by Pearson correlation. The receiver operating characteristic (ROC) curve is used to evaluate the diagnostic value of MEFV and IOS indicators to chronic cough. Results: The C-ACT score of the severe group is significantly lower than that of the control group (P<0.05). FEV1/FVC and PEF of the mild and severe groups are both lower than those of the control group, and FEV1/FVC and PEF of the severe group is lower than those of the mild group (P<0.05). Fres, R5 and X5 of the mild and severe groups are significantly higher than those of the control group, and Fres, R5 and X5 of the severe group are higher than the mild group (P<0.05). FEV1/FVC and PEF are positively correlated with C-ACT score (P<0.05), while Fres, R5 and X5 are negatively correlated with C-ACT score (P<0.05). FEV1/FVC and PEF respectively shows significant negative correlations with Fres, R5 and X5 (P<0.05). R5 has a self-high ROC value of 0.938, followed by Fres, which is 0.917. And the value of IOS diagnostic indicators is higher than展开更多
Early brain development after birth is extremely dynamic,suggest!ng that potential functional changes occur during this period.In this study,the maximal electroshock seizure threshold(MEST)was used to explore the elec...Early brain development after birth is extremely dynamic,suggest!ng that potential functional changes occur during this period.In this study,the maximal electroshock seizure threshold(MEST)was used to explore the electrophysiological variation among three developmental stages in young mice(no more than 5 weeks old).The induced electroshock seizure(ES)behavior of early post natal mice(1-2-weeks old)differed from that during weaning(3 weeks old)and early puberty(4-5-weeks old).Thus,we further explored their respective characteristic responses to the ES parameters.When the stimulation current(SC)was limited to 4.0 mA,only the 1-2-week-old mice were induced to exhibit ES behavior at voltages of 30 V and 40 V,indicating they were more sensitive to maximal electroshock seizure(MES)(response to lower voltage).展开更多
Assume p is an odd prime. We investigate finite p-groups all of whose minimal nonabelian subgroups are of order p^3. Let P1-groups denote the p-groups all of whose minimal nonabelian subgroups are nonme tacyclic of or...Assume p is an odd prime. We investigate finite p-groups all of whose minimal nonabelian subgroups are of order p^3. Let P1-groups denote the p-groups all of whose minimal nonabelian subgroups are nonme tacyclic of order p^3. In this paper, the P1-groups are classified, and as a by-product, we prove the Hughes' conjecture is true for the P1-groups.展开更多
Let G be a finite group of Lie type E6 over Fq (adjoint or simply connected) and W be the Weyl group of G. We describe maximal tori T such that T has a complement in its algebraic normalizer N(G, T). It is well known ...Let G be a finite group of Lie type E6 over Fq (adjoint or simply connected) and W be the Weyl group of G. We describe maximal tori T such that T has a complement in its algebraic normalizer N(G, T). It is well known that for each maximal torus T of G there exists an element w ∈ W such that N(G, T )/T ■ CW(w). When T does not have a complement isomorphic to CW(w), we show that w has a lift in N(G, T) of the same order.展开更多
In this paper, the authors first consider the global well-posedness of 3-D Boussinesq system, which has variable kinematic viscosity yet without thermal conductivity and buoyancy force, provided that the viscosity coe...In this paper, the authors first consider the global well-posedness of 3-D Boussinesq system, which has variable kinematic viscosity yet without thermal conductivity and buoyancy force, provided that the viscosity coefficient is sufficiently close to some positive constant in L∞and the initial velocity is small enough in B3,10(R3). With some thermal conductivity in the temperature equation and with linear buoyancy force θe3 on the velocity equation in the Boussinesq system, the authors also prove the global well-posedness of such system with initial temperature and initial velocity being sufficiently small in L1(R3)and B3,10(R3) respectively.展开更多
We establish the limiting weak type behaviors of Riesz transforms associated to the Bessel operators on IR+. which are closely related to the best constants of the weak type (1,1) estimates for such operators. Meanwhi...We establish the limiting weak type behaviors of Riesz transforms associated to the Bessel operators on IR+. which are closely related to the best constants of the weak type (1,1) estimates for such operators. Meanwhile, the corresponding results for Hardy-Littlewood maximal operator and fractional maximal operator in Bessel setting are also obtained.展开更多
The pretreatment serum albumin/globulin ratio (AGR)has been used as a prognostic biomarker for various cancer types.However, the prognostic value of the AGR for prostate cancer,especially for metastatic prostate cance...The pretreatment serum albumin/globulin ratio (AGR)has been used as a prognostic biomarker for various cancer types.However, the prognostic value of the AGR for prostate cancer,especially for metastatic prostate cancer (mPCa)after maximal androgen blockade (MAB),remains unclear.The aim of this study was to evaluate the prognostic value of the pretreatment serum AGR for mPCa treated with MAB.This retrospective study included 214 mPCa patients receiving MAB from October 2007 to March 2017. The correlation of the AGR with survival was estimated using Kaplan-Meier analysis and Cox proportional hazards models.The cutoff value of the AGR was 1.45 according to the receiver operating characteristic curve.Kaplan-Meier analysis demonstrated that patients with a low AGR (<1.45)had poor outcomes in terms of progression-free survival (PFS)and cancer-specific survival (CSS). Multivariate Cox analyses showed that the AGR was an independent predictor of PFS (hazard ratio [HR]=0.642;95%confidence interval [CI]:0.430-0.957;P=0.030)and CSS (HR =0.412;95%CI:0.259-0.654;P<0.001).Furthermore,in a subset of 79 patients with normal serum albumin levels (≥40.0 g l^-1),the serum AGR remained an independent predictor of CSS (P=0.009). The pretreatment AGR was an independent prognostic biomarker for PFS and CSS in patients with mPCa receiving MAB.In addition,the AGR remained effective for the prediction of CSS in patients with normal albumin levels (≥40 g l^-1).However,further prospective studies are needed to confirm our conclusions.展开更多
In this article, some necessary and sufficient conditions are shown in order that weighted inequality of the form ∫{f^*>λ}Φ1(λw1)w2dP≤C∫Ω^Φ2(C|f∞|w3)w4dP holds a.e. for uniformly integrable martingales f =...In this article, some necessary and sufficient conditions are shown in order that weighted inequality of the form ∫{f^*>λ}Φ1(λw1)w2dP≤C∫Ω^Φ2(C|f∞|w3)w4dP holds a.e. for uniformly integrable martingales f =(fn)n≥0 with some constant C > 0,where Φ1,Φ2 are Young functions, wi(i = 1,2,3, 4) are weights, f^*=sup n≥0 |fn| and f∞=lim n→∞ fn a.e. As an application, two-weight weak type maximal inequalities of martingales are considered, and particularly a new equivalence condition is presented.展开更多
In this paper,the behavior for commutators of a class of bilinear singular integral operators associated with non-smooth kernels on the product of weighted Lebesgue spaces is considered.By some new maximal functions t...In this paper,the behavior for commutators of a class of bilinear singular integral operators associated with non-smooth kernels on the product of weighted Lebesgue spaces is considered.By some new maximal functions to control the commutators of bilinear singular integral operators and CMO(Rn)functions,compactness for the commutators is proved.展开更多
Predictors of performance can aid coaches and trainers in prescribing exercise programs for rowing athletes. To date, most of the prediction models have been developed for runners and cyclists. Purpose: The aim of thi...Predictors of performance can aid coaches and trainers in prescribing exercise programs for rowing athletes. To date, most of the prediction models have been developed for runners and cyclists. Purpose: The aim of this study was to develop a regression model to predict performance of a simulated 2 kilometer rowing ergometer time trial. Methods: A group of mixed gender rowing athletes (n = 12) completed in a counterbalanced order a 2 kilometer rowing time trial and a continuous progressively incremented graded exercise test on a rowing ergometer. Subjects were 23.91 ± 4.99 years old, weighed 79.14 ± 12.85 kg, were 187.38 ± 12.60 cm, had a VO2max of 55.48 ± 10.32 mL/kg/min and had 3.17 ± 2.79 years of rowing experience. Physiological measures were recorded during both testing protocols. Results: Maximum power/stroke ratio (r =-0.96, p < 0.001), power/stroke ratio at the ventilatory breakpoint (r =-0.90, p < 0.001), maximal oxygen uptake (r =-0.84, p < 0.001) and oxygen uptake at the ventilatory breakpoint (r =-0.82, p < 0.001) were found to be strong and significant predictors of 2 kilometer rowing performance. Conclusion: The four significant predictors of rowing performance suggest training should focus on improving both aerobic capacity and strength. Practical Application: Rowing training should focus on developing hip and leg aerobic and anaerobic capacities to improve performance. Developing strength improves mechanical efficiency as well as raising anaerobic thresholds allowing athletes to utilize a larger portion of their aerobic capacity.展开更多
Background: Children are affected by disorders that have an impact on the respiratory muscles. Inspiratory muscle function can be assessed by means of the noninvasive tension–time index of the inspiratory muscles(TTI...Background: Children are affected by disorders that have an impact on the respiratory muscles. Inspiratory muscle function can be assessed by means of the noninvasive tension–time index of the inspiratory muscles(TTImus). Our objectives were to identify the determinants of TTImus in healthy children and to report normal values of TTImus in this population.Methods: We measured weight, height, upper arm muscle area(UAMA), and TTImusin 96 children aged 6–18 years. The level and frequency of aerobic activity was assessed by questionnaire.Results: TTImuswas significantly lower in male subjects(0.095 ± 0.038, mean ± SD) compared with female subjects(0.126 ± 0.056)(p = 0.002).TTImus was significantly lower in regularly exercising(0.093 ± 0.040) compared with nonexercising subjects(0.130 ± 0.053)(p < 0.001). TTImus was significantly negatively related to age(r =-0.239, p = 0.019), weight(r =-0.214, p = 0.037), height(r =-0.355, p < 0.001), and UAMA(r =-0.222, p = 0.030). Multivariate logistic regression analysis revealed that height and aerobic exercise were significantly related to TTImus independently of age, weight, and UAMA. The predictive regression equation for TTImus in male subjects was TTImus = 0.228-0.001 × height(cm), and in female subjects it was TTImus = 0.320-0.001 × height(cm).Conclusion: Gender, age, anthropometry, skeletal muscularity, and aerobic exercise are significantly associated with indices of inspiratory muscle function in children. Normal values of TTImus in healthy children are reported.展开更多
Mode decision-maker is a critical component in the logic-based Integrated Estimation and Guidance(IEG) system. For the best possible estimation and guidance performance, the mode decision delay of the mode decision-ma...Mode decision-maker is a critical component in the logic-based Integrated Estimation and Guidance(IEG) system. For the best possible estimation and guidance performance, the mode decision delay of the mode decision-maker should be limited to a range as small as possible. This paper presents a numerical method for computing the maximal admissible mode decision delay that varies with time-to-go. Particular attention has been paid to highly maneuvering target interception in terminal guidance. The results of this research offer useful guidelines for the design of the mode decision-maker in IEG systems.展开更多
In this article,we introduce the martingale Musielak-Orlicz Hardy spaces H_φ^*(■),Pφ(?),H_φ^S(■),Qφ(?)and H_φ^s(■),respectively,via the maximal function,the quadratic variation and the conditional quadratic va...In this article,we introduce the martingale Musielak-Orlicz Hardy spaces H_φ^*(■),Pφ(?),H_φ^S(■),Qφ(?)and H_φ^s(■),respectively,via the maximal function,the quadratic variation and the conditional quadratic variation of martingales.We then establish the atomic characterizations of H_φ^s(■),Pφ(■)and Qφ(■).As applications,we obtain the dual space of H_φ^s(■)and several martingale inequalities which further clarify the relations among H_φ^*(■),Pφ(■),H_φ^S(■),Qφ(■)and H_φ^s(■).Especially,as special cases,the results on atomic characterizations of H_φ^s(■),Pφ(?)and Qφ(■)as well as on the dual space of H_φ^s(■)in the weighted case are also new.展开更多
The authors generalize the Fenchel theorem for strong spacelike closed curves of index 1 in the 3-dimensional Minkowski space, showing that the total curvature must be less than or equal to 2π. Here the strong spacel...The authors generalize the Fenchel theorem for strong spacelike closed curves of index 1 in the 3-dimensional Minkowski space, showing that the total curvature must be less than or equal to 2π. Here the strong spacelike condition means that the tangent vector and the curvature vector span a spacelike 2-plane at each point of the curve γ under consideration. The assumption of index 1 is equivalent to saying that γ winds around some timelike axis with winding number 1. This reversed Fenchel-type inequality is proved by constructing a ruled spacelike surface with the given curve as boundary and applying the Gauss-Bonnet formula. As a by-product, this shows the existence of a maximal surface with γ as the boundary.展开更多
In this paper, the authors give the local L2 estimate of the maximal operator Sφ,γ* of the operator family {St,φ,γ} defined initially by ■which is the solution(when n = 1) of the following dispersive equations(*)...In this paper, the authors give the local L2 estimate of the maximal operator Sφ,γ* of the operator family {St,φ,γ} defined initially by ■which is the solution(when n = 1) of the following dispersive equations(*) along a curve γ:■where φ : R+→R satisfies some suitable conditions and φ((-?)1/2) is a pseudo-differential operator with symbol φ(|ξ|). As a consequence of the above result, the authors give the pointwise convergence of the solution(when n = 1) of the equation(*) along curve γ.Moreover, a global L2 estimate of the maximal operator Sφ,γ* is also given in this paper.展开更多
In the present paper, the rigidity of hypersurfaces in Euclidean space is revisited.The Darboux equation is highlighted and two new proofs of the rigidity are given via energy method and maximal principle, respectively.
We study properties of graded maximal Cohen-Macaulay modules over an N-graded locally finite,Auslander Gorenstein,and Cohen-Macaulay algebra of dimension two.As a consequence,we extend a part of the McKay corresponden...We study properties of graded maximal Cohen-Macaulay modules over an N-graded locally finite,Auslander Gorenstein,and Cohen-Macaulay algebra of dimension two.As a consequence,we extend a part of the McKay correspondence in dimension two to a more general setting.展开更多
Purpose: This study’s purpose was to examine whether established risk categories of waist circumference(WC)-normal, high risk, and very high health risk-reflected significant differences in cardiorespiratory fitness(...Purpose: This study’s purpose was to examine whether established risk categories of waist circumference(WC)-normal, high risk, and very high health risk-reflected significant differences in cardiorespiratory fitness(CRF) and physical activity(PA) level.Methods: CRF was directly measured as maximal oxygen uptake during a progressive graded treadmill test to exhaustion in 722 individuals(349 women) aged 20à85 years. WC was measured between the lower rib and the iliac crest. Objectively measured PA was assessed using an accelerometer.Results: Men in the normal risk group(WC < 94 cm) had a 31% higher CRF and 43% higher level of moderate-to-vigorous PA than men in the very high risk group(with a WC > 102 cm). Corresponding numbers for women within normal(WC < 80 cm) and very high risk group(WC > 88 cm) were 25% and 18%(p < 0.05). There was a high negative correlation between CRF and WC in men(r = -0.68), and a moderate correlation for women(r = -0.49;p < 0.001). For each cm increase in WC, CRF was reduced by 0.48 and 0.27 mL/kg/min in men and women,respectively(p < 0.001).Conclusion: The recommended WC thresholds for abdominal obesity reflected significant differences in CRF for both men and women, and could serve as a useful instrument for estimating health-related differences in CRF.展开更多
Via the boundedness of intrinsic g-functions from the Hardy spaces with variable exponent,Hp(·)(Rn),into Lebesgue spaces with variable exponent,Lp(·) (Rn),and establishing some estimates on a discrete Little...Via the boundedness of intrinsic g-functions from the Hardy spaces with variable exponent,Hp(·)(Rn),into Lebesgue spaces with variable exponent,Lp(·) (Rn),and establishing some estimates on a discrete Littlewood-Paley g-function and a Peetre-type maximal function,we obtain several equivalent characterizations of Hp(·)(Rn) in terms of wavelets,which extend the wavelet characterizations of the classical Hardy spaces.The main ingredients are that,we overcome the difficulties of the quasi-norms of Hp(·)(Rn) by elaborately using an observation and the Fefferman-Stein vector-valued maximal inequality on Lp(·)(Rn),and also overcome the difficulty of the failure of q =2 in the atomic decomposition of Hp(·) (Rn) by a known idea.展开更多
基金supported in part the National Natural Science Foundation of China (Grant No. 11771046)the Project from the Ministry of Education in Chinathe Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Based on a series of recent papers, a powerful algorithm is reformulated for computing the maximal eigenpair of self-adjoint complex tridiagonal matrices. In parallel, the same problem in a particular case for computing the sub-maximal eigenpair is also introduced. The key ideas for each critical improvement are explained. To illustrate the present algorithm and compare it with the related algorithms, more than 10 examples are included.
基金Qinhuangdao Science and Technology Research and Development Plan of Hebei Province.Project No:201502A179.
文摘Objective:The article aims to investigate the relationship of parameters such as airway vicosity resistance (R5) and maximal expiratory flow-volume curve (MEFV) with severity of chronic cough in 3 to 5 years old children by impulse oscillometry (IOS) detection when the oscillation frequency is 5Hz.Method: The article chooses eighty children with chronic cough who were diagnosed or treated in our hospital from March 2017 to March 2018 as the research group, and chooses 50 healthy children who had physical examination in our hospital as the control group. Children's asthma control test (C-ACT) is used to assess the disease severity of children. MEFV detection is carried out to the two groups of children to obtain the ratio of forced expiratory volume in one second and forced vital capacity (FEV1/FVC) and the peak expiratory flow (PEF). LsS inductance (X5) is detected by IOS when R5, the resonant frequency (Fres), and the oscillation frequency is 5Hz. The relationship of ACT score with MEFV and IOS indicators is analyzed by Pearson correlation. The receiver operating characteristic (ROC) curve is used to evaluate the diagnostic value of MEFV and IOS indicators to chronic cough. Results: The C-ACT score of the severe group is significantly lower than that of the control group (P<0.05). FEV1/FVC and PEF of the mild and severe groups are both lower than those of the control group, and FEV1/FVC and PEF of the severe group is lower than those of the mild group (P<0.05). Fres, R5 and X5 of the mild and severe groups are significantly higher than those of the control group, and Fres, R5 and X5 of the severe group are higher than the mild group (P<0.05). FEV1/FVC and PEF are positively correlated with C-ACT score (P<0.05), while Fres, R5 and X5 are negatively correlated with C-ACT score (P<0.05). FEV1/FVC and PEF respectively shows significant negative correlations with Fres, R5 and X5 (P<0.05). R5 has a self-high ROC value of 0.938, followed by Fres, which is 0.917. And the value of IOS diagnostic indicators is higher than
基金the National Natural Science Foundation of China(81403191)and Yunnan Provincial Natural Science Foundation(2018FB11&2015FA004,and KKSY201626001).
文摘Early brain development after birth is extremely dynamic,suggest!ng that potential functional changes occur during this period.In this study,the maximal electroshock seizure threshold(MEST)was used to explore the electrophysiological variation among three developmental stages in young mice(no more than 5 weeks old).The induced electroshock seizure(ES)behavior of early post natal mice(1-2-weeks old)differed from that during weaning(3 weeks old)and early puberty(4-5-weeks old).Thus,we further explored their respective characteristic responses to the ES parameters.When the stimulation current(SC)was limited to 4.0 mA,only the 1-2-week-old mice were induced to exhibit ES behavior at voltages of 30 V and 40 V,indicating they were more sensitive to maximal electroshock seizure(MES)(response to lower voltage).
基金National Natural Science Foundation of China (Grant Nos. 11771258 and 11471198).
文摘Assume p is an odd prime. We investigate finite p-groups all of whose minimal nonabelian subgroups are of order p^3. Let P1-groups denote the p-groups all of whose minimal nonabelian subgroups are nonme tacyclic of order p^3. In this paper, the P1-groups are classified, and as a by-product, we prove the Hughes' conjecture is true for the P1-groups.
基金Russian Science Foundation (project no. 14-21-00065).
文摘Let G be a finite group of Lie type E6 over Fq (adjoint or simply connected) and W be the Weyl group of G. We describe maximal tori T such that T has a complement in its algebraic normalizer N(G, T). It is well known that for each maximal torus T of G there exists an element w ∈ W such that N(G, T )/T ■ CW(w). When T does not have a complement isomorphic to CW(w), we show that w has a lift in N(G, T) of the same order.
基金supported by the National Natural Science Foundation of China(Nos.11731007,11688101)Innovation Grant from National Center for Mathematics and Interdisciplinary Sciences.
文摘In this paper, the authors first consider the global well-posedness of 3-D Boussinesq system, which has variable kinematic viscosity yet without thermal conductivity and buoyancy force, provided that the viscosity coefficient is sufficiently close to some positive constant in L∞and the initial velocity is small enough in B3,10(R3). With some thermal conductivity in the temperature equation and with linear buoyancy force θe3 on the velocity equation in the Boussinesq system, the authors also prove the global well-posedness of such system with initial temperature and initial velocity being sufficiently small in L1(R3)and B3,10(R3) respectively.
文摘We establish the limiting weak type behaviors of Riesz transforms associated to the Bessel operators on IR+. which are closely related to the best constants of the weak type (1,1) estimates for such operators. Meanwhile, the corresponding results for Hardy-Littlewood maximal operator and fractional maximal operator in Bessel setting are also obtained.
基金the Fundamental Research Funds for the Central Universities of Central South University (Grant No.2017zztsg03).
文摘The pretreatment serum albumin/globulin ratio (AGR)has been used as a prognostic biomarker for various cancer types.However, the prognostic value of the AGR for prostate cancer,especially for metastatic prostate cancer (mPCa)after maximal androgen blockade (MAB),remains unclear.The aim of this study was to evaluate the prognostic value of the pretreatment serum AGR for mPCa treated with MAB.This retrospective study included 214 mPCa patients receiving MAB from October 2007 to March 2017. The correlation of the AGR with survival was estimated using Kaplan-Meier analysis and Cox proportional hazards models.The cutoff value of the AGR was 1.45 according to the receiver operating characteristic curve.Kaplan-Meier analysis demonstrated that patients with a low AGR (<1.45)had poor outcomes in terms of progression-free survival (PFS)and cancer-specific survival (CSS). Multivariate Cox analyses showed that the AGR was an independent predictor of PFS (hazard ratio [HR]=0.642;95%confidence interval [CI]:0.430-0.957;P=0.030)and CSS (HR =0.412;95%CI:0.259-0.654;P<0.001).Furthermore,in a subset of 79 patients with normal serum albumin levels (≥40.0 g l^-1),the serum AGR remained an independent predictor of CSS (P=0.009). The pretreatment AGR was an independent prognostic biomarker for PFS and CSS in patients with mPCa receiving MAB.In addition,the AGR remained effective for the prediction of CSS in patients with normal albumin levels (≥40 g l^-1).However,further prospective studies are needed to confirm our conclusions.
基金the National Natural Science Foundation of China (11871195).
文摘In this article, some necessary and sufficient conditions are shown in order that weighted inequality of the form ∫{f^*>λ}Φ1(λw1)w2dP≤C∫Ω^Φ2(C|f∞|w3)w4dP holds a.e. for uniformly integrable martingales f =(fn)n≥0 with some constant C > 0,where Φ1,Φ2 are Young functions, wi(i = 1,2,3, 4) are weights, f^*=sup n≥0 |fn| and f∞=lim n→∞ fn a.e. As an application, two-weight weak type maximal inequalities of martingales are considered, and particularly a new equivalence condition is presented.
基金the Natural Science Foundation of Shandong Province(Nos.ZR2018PA004 and ZR2016AB07)the National Natural Science Foundation of China(Nos.11571306 and 11671363).
文摘In this paper,the behavior for commutators of a class of bilinear singular integral operators associated with non-smooth kernels on the product of weighted Lebesgue spaces is considered.By some new maximal functions to control the commutators of bilinear singular integral operators and CMO(Rn)functions,compactness for the commutators is proved.
基金This study was completed with the help of dissertation committee members, Fredric Goss, Ph.D., Robert Robertson, Ph.D., Elizabeth Nagle, Ph.D. and Jonathan Abt, Ph.D. and the help of the Center for Health and Fitness Research at the University of Pittsburgh, University of Pittsburgh Crew Team and Row Fit Rowing Club. The study completed was not done with financial or professional interest from manufactures or companies that could potentially benefit from the results. This study did not receive grant support. The results of this present study do not constitute endorsement of the product by the authors of the NSCA.
文摘Predictors of performance can aid coaches and trainers in prescribing exercise programs for rowing athletes. To date, most of the prediction models have been developed for runners and cyclists. Purpose: The aim of this study was to develop a regression model to predict performance of a simulated 2 kilometer rowing ergometer time trial. Methods: A group of mixed gender rowing athletes (n = 12) completed in a counterbalanced order a 2 kilometer rowing time trial and a continuous progressively incremented graded exercise test on a rowing ergometer. Subjects were 23.91 ± 4.99 years old, weighed 79.14 ± 12.85 kg, were 187.38 ± 12.60 cm, had a VO2max of 55.48 ± 10.32 mL/kg/min and had 3.17 ± 2.79 years of rowing experience. Physiological measures were recorded during both testing protocols. Results: Maximum power/stroke ratio (r =-0.96, p < 0.001), power/stroke ratio at the ventilatory breakpoint (r =-0.90, p < 0.001), maximal oxygen uptake (r =-0.84, p < 0.001) and oxygen uptake at the ventilatory breakpoint (r =-0.82, p < 0.001) were found to be strong and significant predictors of 2 kilometer rowing performance. Conclusion: The four significant predictors of rowing performance suggest training should focus on improving both aerobic capacity and strength. Practical Application: Rowing training should focus on developing hip and leg aerobic and anaerobic capacities to improve performance. Developing strength improves mechanical efficiency as well as raising anaerobic thresholds allowing athletes to utilize a larger portion of their aerobic capacity.
文摘Background: Children are affected by disorders that have an impact on the respiratory muscles. Inspiratory muscle function can be assessed by means of the noninvasive tension–time index of the inspiratory muscles(TTImus). Our objectives were to identify the determinants of TTImus in healthy children and to report normal values of TTImus in this population.Methods: We measured weight, height, upper arm muscle area(UAMA), and TTImusin 96 children aged 6–18 years. The level and frequency of aerobic activity was assessed by questionnaire.Results: TTImuswas significantly lower in male subjects(0.095 ± 0.038, mean ± SD) compared with female subjects(0.126 ± 0.056)(p = 0.002).TTImus was significantly lower in regularly exercising(0.093 ± 0.040) compared with nonexercising subjects(0.130 ± 0.053)(p < 0.001). TTImus was significantly negatively related to age(r =-0.239, p = 0.019), weight(r =-0.214, p = 0.037), height(r =-0.355, p < 0.001), and UAMA(r =-0.222, p = 0.030). Multivariate logistic regression analysis revealed that height and aerobic exercise were significantly related to TTImus independently of age, weight, and UAMA. The predictive regression equation for TTImus in male subjects was TTImus = 0.228-0.001 × height(cm), and in female subjects it was TTImus = 0.320-0.001 × height(cm).Conclusion: Gender, age, anthropometry, skeletal muscularity, and aerobic exercise are significantly associated with indices of inspiratory muscle function in children. Normal values of TTImus in healthy children are reported.
文摘Mode decision-maker is a critical component in the logic-based Integrated Estimation and Guidance(IEG) system. For the best possible estimation and guidance performance, the mode decision delay of the mode decision-maker should be limited to a range as small as possible. This paper presents a numerical method for computing the maximal admissible mode decision delay that varies with time-to-go. Particular attention has been paid to highly maneuvering target interception in terminal guidance. The results of this research offer useful guidelines for the design of the mode decision-maker in IEG systems.
基金National Natural Science Foundation of China (Grant Nos.11471337, 11722114, 11571039 and 11671185).
文摘In this article,we introduce the martingale Musielak-Orlicz Hardy spaces H_φ^*(■),Pφ(?),H_φ^S(■),Qφ(?)and H_φ^s(■),respectively,via the maximal function,the quadratic variation and the conditional quadratic variation of martingales.We then establish the atomic characterizations of H_φ^s(■),Pφ(■)and Qφ(■).As applications,we obtain the dual space of H_φ^s(■)and several martingale inequalities which further clarify the relations among H_φ^*(■),Pφ(■),H_φ^S(■),Qφ(■)and H_φ^s(■).Especially,as special cases,the results on atomic characterizations of H_φ^s(■),Pφ(?)and Qφ(■)as well as on the dual space of H_φ^s(■)in the weighted case are also new.
基金the National Natural Science Foundation of China(No.11471021)the Fundamental Research Funds for the Central Universities of China(No.531107050874).
文摘The authors generalize the Fenchel theorem for strong spacelike closed curves of index 1 in the 3-dimensional Minkowski space, showing that the total curvature must be less than or equal to 2π. Here the strong spacelike condition means that the tangent vector and the curvature vector span a spacelike 2-plane at each point of the curve γ under consideration. The assumption of index 1 is equivalent to saying that γ winds around some timelike axis with winding number 1. This reversed Fenchel-type inequality is proved by constructing a ruled spacelike surface with the given curve as boundary and applying the Gauss-Bonnet formula. As a by-product, this shows the existence of a maximal surface with γ as the boundary.
基金the National Natural Science Foundation of China(Nos.11571160,11661061,11761054)the Inner Mongolia University Scientific Research Projects(Nos.NJZZ16234,NJZY17289).
文摘In this paper, the authors give the local L2 estimate of the maximal operator Sφ,γ* of the operator family {St,φ,γ} defined initially by ■which is the solution(when n = 1) of the following dispersive equations(*) along a curve γ:■where φ : R+→R satisfies some suitable conditions and φ((-?)1/2) is a pseudo-differential operator with symbol φ(|ξ|). As a consequence of the above result, the authors give the pointwise convergence of the solution(when n = 1) of the equation(*) along curve γ.Moreover, a global L2 estimate of the maximal operator Sφ,γ* is also given in this paper.
基金the National Natural Science Foundation of China(No.11871160)the Fundamental Research Funds for the Central Universities of China(No.ZYGX2016J135).
文摘In the present paper, the rigidity of hypersurfaces in Euclidean space is revisited.The Darboux equation is highlighted and two new proofs of the rigidity are given via energy method and maximal principle, respectively.
基金The authors thank the referees for the careful reading and very useful suggestions and thank Ken Brown,Daniel Rogalski,Robert Won,and Quanshui Wu for many useful conversations and valuable comments on the subject.Y.-H.Wang and X.-S.Qin thank the Department of Mathematics,University of Washington for its very supportive hospitality during their visitsX.-S.Qin was partially supported by the Foundation of China Scholarship Council(Grant No.[2016]3100)+3 种基金Y.-H.Wang was partially supported by the National Natural Science Foundation of China(Grant Nos.11971289,11871071)the Foundation of Shanghai Science and Technology Committee(Grant No.15511107300)the Foundation of China Scholarship Council(Grant No.[2016]3009)J.J.Zhang was partially supported by the US National Science Foundation(Grant No.DMS-1700825).
文摘We study properties of graded maximal Cohen-Macaulay modules over an N-graded locally finite,Auslander Gorenstein,and Cohen-Macaulay algebra of dimension two.As a consequence,we extend a part of the McKay correspondence in dimension two to a more general setting.
基金funded by The Norwegian Directorate of Health and the Norwegian School of Sport Sciences.
文摘Purpose: This study’s purpose was to examine whether established risk categories of waist circumference(WC)-normal, high risk, and very high health risk-reflected significant differences in cardiorespiratory fitness(CRF) and physical activity(PA) level.Methods: CRF was directly measured as maximal oxygen uptake during a progressive graded treadmill test to exhaustion in 722 individuals(349 women) aged 20à85 years. WC was measured between the lower rib and the iliac crest. Objectively measured PA was assessed using an accelerometer.Results: Men in the normal risk group(WC < 94 cm) had a 31% higher CRF and 43% higher level of moderate-to-vigorous PA than men in the very high risk group(with a WC > 102 cm). Corresponding numbers for women within normal(WC < 80 cm) and very high risk group(WC > 88 cm) were 25% and 18%(p < 0.05). There was a high negative correlation between CRF and WC in men(r = -0.68), and a moderate correlation for women(r = -0.49;p < 0.001). For each cm increase in WC, CRF was reduced by 0.48 and 0.27 mL/kg/min in men and women,respectively(p < 0.001).Conclusion: The recommended WC thresholds for abdominal obesity reflected significant differences in CRF for both men and women, and could serve as a useful instrument for estimating health-related differences in CRF.
基金The author would like to express his deep thanks to the anonymous referees for their several enlightening comments on this article, which do improve the presen tat ion of this article. This work was supported in part by the National Natural Science Foundation of China (Grant Nos. 11701160, 11871100).
文摘Via the boundedness of intrinsic g-functions from the Hardy spaces with variable exponent,Hp(·)(Rn),into Lebesgue spaces with variable exponent,Lp(·) (Rn),and establishing some estimates on a discrete Littlewood-Paley g-function and a Peetre-type maximal function,we obtain several equivalent characterizations of Hp(·)(Rn) in terms of wavelets,which extend the wavelet characterizations of the classical Hardy spaces.The main ingredients are that,we overcome the difficulties of the quasi-norms of Hp(·)(Rn) by elaborately using an observation and the Fefferman-Stein vector-valued maximal inequality on Lp(·)(Rn),and also overcome the difficulty of the failure of q =2 in the atomic decomposition of Hp(·) (Rn) by a known idea.