In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by re...In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors.展开更多
Ovarian cancer remains a leading cause of gynecological cancer mortality1,and patients with advanced stage ovarian cancer frequently develop malignant ascites that foster immunosuppressive microenvironments and therap...Ovarian cancer remains a leading cause of gynecological cancer mortality1,and patients with advanced stage ovarian cancer frequently develop malignant ascites that foster immunosuppressive microenvironments and therapeutic resistance2,3.Although ascites have traditionally been considered detrimental,we report a paradoxical role in which they enhance the cytotoxicity ofγδT cells—a unique T cell subset that can be allogenically transferred for cancer treatment4,5—toward ovarian cancer.展开更多
BACKGROUND Patients with acute-on-chronic liver failure(ACLF)experience severe immune dysfunction.Liver transplantation(LT)significantly improves survival outcomes.However,the characteristics of peripheral blood lymph...BACKGROUND Patients with acute-on-chronic liver failure(ACLF)experience severe immune dysfunction.Liver transplantation(LT)significantly improves survival outcomes.However,the characteristics of peripheral blood lymphocyte subsets(PBLSs)in this patient population are not well defined,and the dynamics of immune reconstitution post-LT are insufficiently understood.AIM To characterize PBLSs in patients with ACLF prior to LT and to evaluate PBLS reconstitution after LT.METHODS Clinical data from patients undergoing LT in the Transplantation Center,The Third Xiangya Hospital from January 2022 to December 2023 were analyzed retrospectively.Our cohort comprised 44 patients with ACLF,16 patients with acute decompensation of cirrhosis,and 23 patients with compensated cirrhosis.Twenty healthy volunteers were included as controls.PBLSs were evaluated across all groups.The relationship between PBLSs and post-LT prognosis was assessed,and dynamic changes in PBLSs among patients with ACLF were analyzed at different time points.RESULTS Patients with ACLF exhibited a marked reduction in PBLSs compared with healthy volunteers.Natural killer(NK)cell counts were further reduced in patients with ACLF when compared with patients with compensated cirrhosis.PBLSs did not correlate with the etiology or severity of ACLF or with established liver failure scores.Following LT,a rapid restoration of NK cells and B cells was observed in patients with ACLF.However,the cluster of differentiation(CD)3+T cell and CD4+T cell counts decreased 14 days post-LT and subsequently returned to preoperative levels by day 21.CONCLUSION Patients with ACLF exhibited markedly reduced PBLSs,with decreased NK cells potentially linked to progression from compensated cirrhosis to liver failure.NK and B cell were rapidly restored after LT.展开更多
In modal logic,topological semantics is an intuitive and natural special case of neighbourhood semantics.This paper stems from the observation that the satisfaction relation of topological semantics applies to subset ...In modal logic,topological semantics is an intuitive and natural special case of neighbourhood semantics.This paper stems from the observation that the satisfaction relation of topological semantics applies to subset spaces which are more general than topological spaces.The minimal modal logic which is strongly sound and complete with respect to the class of subset spaces is found.Soundness and completeness results of some famous modal logics(e.g.S4,S5 and Tr)with respect to various important classes of subset spaces(eg intersection structures and complete fields of sets)are also proved.In the meantime,some known results,e.g.the soundness and completeness of Tr with respect to the class of discrete topological spaces,are proved directly using some modifications of the method of canonical mode1,without a detour via neighbourhood semantics or relational semantics.展开更多
The stratospheric airship is affected by harsh conditions in the stratosphere environment.To ensure the safety of the airship,it is necessary to detect the material state of the airship envelope.Since digital image co...The stratospheric airship is affected by harsh conditions in the stratosphere environment.To ensure the safety of the airship,it is necessary to detect the material state of the airship envelope.Since digital image correlation possesses non-contact strain measurement ability,this paper explores the infuence of different shapes of the subset on measurement accuracy.Through the results,it is found that increasing the aspect ratio of subsets can improve the strain accuracy measured in the c-direction,and reducing the aspect ratio can improve the strain accuracy measured in the y-direction.This trend becomes more obvious as the strain increases.Based on this discovery,a subset adaptive algorithm is proposed.The feasibility of the algorithm is verified by experiments,and the precision of strain measurement can be effectively improved by adjusting the threshold value.Therefore,the algorithm can be utilized to increase the measurement accuracy in the larger strain direction without changing the size of the subset.展开更多
This article constructs statistical selection procedures for exponential populations that may differ in only the threshold parameters. The scale parameters of the populations are assumed common and known. The independ...This article constructs statistical selection procedures for exponential populations that may differ in only the threshold parameters. The scale parameters of the populations are assumed common and known. The independent samples drawn from the populations are taken to be of the same size. The best population is defined as the one associated with the largest threshold parameter. In case more than one population share the largest threshold, one of these is tagged at random and denoted the best. Two procedures are developed for choosing a subset of the populations having the property that the chosen subset contains the best population with a prescribed probability. One procedure is based on the sample minimum values drawn from the populations, and another is based on the sample means from the populations. An “Indifference Zone” (IZ) selection procedure is also developed based on the sample minimum values. The IZ procedure asserts that the population with the largest test statistic (e.g., the sample minimum) is the best population. With this approach, the sample size is chosen so as to guarantee that the probability of a correct selection is no less than a prescribed probability in the parameter region where the largest threshold is at least a prescribed amount larger than the remaining thresholds. Numerical examples are given, and the computer R-codes for all calculations are given in the Appendices.展开更多
Aimed at the problem of the low computational efficiency of the existing urethral-valve reliability analysis,an efficient reliability analysis method of the wireless energy-transmitting urethral-valve(WETUV)was propos...Aimed at the problem of the low computational efficiency of the existing urethral-valve reliability analysis,an efficient reliability analysis method of the wireless energy-transmitting urethral-valve(WETUV)was proposed.The method is called FTA-AK-SS,based on the active learning Kriging(AK)model,subset simulation(SS)algorithm,and fault tree analysis(FTA).According to the principle of FTA,we established the fault tree model of the WETUV to determine its minimum cut set and bottom events.Then we defined the random variables affecting its reliability.The U learning function was used to selectively add the sample points of random variables to update the initial Kriging surrogate model.At the same time,combined with the SS algorithm,the reliability and sensitivity analyses of the WETUV were realized.The result shows that compared with the traditional Monte Carlo simulation and FTA-Kriging-SS methods,the proposed method significantly improves the calculation efficiency of the WETUV under the premise of ensuring calculation accuracy.The reliability of the WETUV is greatly affected by the rubber pad’s aging,the receiver coil’s corrosion,and the position deviation.This study can provide a new way to realize a high-efficiency reliability calculation and analysis for urethral valves.展开更多
The fatigue of heavy-haul railway bridges is considered a key concern due to high stress levels and cyclic loading.The evaluation of fatigue reliability is required to include factor correlations.A major challenge is ...The fatigue of heavy-haul railway bridges is considered a key concern due to high stress levels and cyclic loading.The evaluation of fatigue reliability is required to include factor correlations.A major challenge is presented by the construction of the cumulative distribution function(CDF)and the description of correlations between random variables.In this study,the copula function is used to analyze the fatigue failure probability of the Shuohuang heavy-haul railway bridge.A C-vine copula(CVC)-based joint probability density function(JPDF)is derived with eight correlated parameters.To enhance efficiency in small failure probability calculations,the subset simulation and most probable point(MPP)Monte Carlo importance sampling are introduced based on the Rosenblatt transform and C-vine model.Comparisons with traditional Monte Carlo methods confirm that high accuracy and efficiency are achieved.The results show that when parameter correlations are ignored,failure probability is underestimated,increasing safety risks in bridge assessments.展开更多
In order to meet the requirements of combustion optimization for saving energy and reducing pollutant emission simultaneously,an immune cell subsets based multiobjective optimization algorithm（ICSMOA）is proposed.In ...In order to meet the requirements of combustion optimization for saving energy and reducing pollutant emission simultaneously,an immune cell subsets based multiobjective optimization algorithm（ICSMOA）is proposed.In the ICSMOA,the subset division operator and the immunological tolerance operation are defined.Preference can be easily addressed by using the subset division operator,and the distribution of the solutions can be guaranteed by the immunological tolerance operation.Using the ICSMOA,a group of Pareto optimal solutions can be obtained.However,by the traditional weighting method（WM）,only one solution can be obtained and it cannot be judged as Pareto optimal or not.In contrast to the solutions obtained by the repeatedly performed WM,the simulation results show that most solutions obtained by the ICSMOA are better than the solutions obtained by the WM.In addition,the Pareto front obtained by the ICSMOA is not as uniform as most classical multiobjective optimization algorithms.More optimal solutions which meet the preference set by the decision-maker can be obtained and they are very useful for industrial application.展开更多
There are some limitations when we apply conventional methods to analyze the massive amounts of seismic data acquired with high-density spatial sampling since processors usually obtain the properties of raw data from ...There are some limitations when we apply conventional methods to analyze the massive amounts of seismic data acquired with high-density spatial sampling since processors usually obtain the properties of raw data from common shot gathers or other datasets located at certain points or along lines. We propose a novel method in this paper to observe seismic data on time slices from spatial subsets. The composition of a spatial subset and the unique character of orthogonal or oblique subsets are described and pre-stack subsets are shown by 3D visualization. In seismic data processing, spatial subsets can be used for the following aspects： （1） to check the trace distribution uniformity and regularity; （2） to observe the main features of ground-roll and linear noise; （3） to find abnormal traces from slices of datasets; and （4） to QC the results of pre-stack noise attenuation. The field data application shows that seismic data analysis in spatial subsets is an effective method that may lead to a better discrimination among various wavefields and help us obtain more information.展开更多
A new method that uses a modified ordered subsets （MOS） algorithm to improve the convergence rate of space-alternating generalized expectation-maximization （SAGE） algorithm for positron emission tomography （PET）...A new method that uses a modified ordered subsets （MOS） algorithm to improve the convergence rate of space-alternating generalized expectation-maximization （SAGE） algorithm for positron emission tomography （PET） image reconstruction is proposed.In the MOS-SAGE algorithm,the number of projections and the access order of the subsets are modified in order to improve the quality of the reconstructed images and accelerate the convergence speed.The number of projections in a subset increases as follows：2,4,8,16,32 and 64.This sequence means that the high frequency component is recovered first and the low frequency component is recovered in the succeeding iteration steps.In addition,the neighboring subsets are separated as much as possible so that the correlation of projections can be decreased and the convergences can be speeded up.The application of the proposed method to simulated and real images shows that the MOS-SAGE algorithm has better performance than the SAGE algorithm and the OSEM algorithm in convergence and image quality.展开更多
Objective To compare effects of combined acupuncture and general anesthesia （CAGA） and general anesthesia （GA） on immune function in patients of laparoscopic cholecystectomy （LC） in peri-operative period. Method...Objective To compare effects of combined acupuncture and general anesthesia （CAGA） and general anesthesia （GA） on immune function in patients of laparoscopic cholecystectomy （LC） in peri-operative period. Methods Thirty-nine cases undergoing LC were randomly divided into a CAGA group and a GA group. The CAGA group was treated with electroacupuncture at Hegu （合谷- LI 4）, Neiguan （内关PC 6）, Zusanli （足三里ST 36） and Yanglingquan （阳陵泉 GB 34） for 15-30 minutes followed by the general anesthesia, and the continuous electroacupuncture stimulation was given till the operation finished. The GA group was treated with simple general anesthesia. Changes of T cell subsets, tumor necrosis factor-alpha （TNF-α） and interleukin-6 （IL-6） were observed before anesthesia induction, and 2 hours, 1st and 3 rd day after operation, and the adverse reaction after operation was recorded. Results At 2 hours after operation, the percentages of CD3 and CDs in both groups were significantly lower than those before anesthesia induction （all P〈0.05）, and the percentage of CD4 in the GA group decreased significantly （P〈0.05）, while the percentage of CD： did not significantly change and CD4/CD8 increased significantly in the CAGA group （P〈0.05）. At 3 days after operation, the level of TNF-α in the ACGA group decreased significantly as compared with that before anesthesia induction （P〈0.05）. The cases with nausea after operation in the CAGA group were significantly less than those in the GA group （P〈0.05）. Conclusion Acupuncture combined with general anesthesia has a little effect on immune function in patients of LC with less adverse reactions.展开更多
Objective: To study the expression of Fas and Bcl-2proteins on T lymphocyte subsets in the peripheralblood of relapsing patients with condyloma acuminatum(CA) and healthy controls. Methods: Flow cytometry (permeabizat...Objective: To study the expression of Fas and Bcl-2proteins on T lymphocyte subsets in the peripheralblood of relapsing patients with condyloma acuminatum(CA) and healthy controls. Methods: Flow cytometry (permeabization andstaining procedure with conjugated antibodies) wasused. Results: We observed that the expression of Fasprotein on CD4^+ T lymphocyte subset of CA patientswas significantly higher than that of healthy controls(P<0.01). Conclusions: Increased expression of Fas proteinon CD4^+ T lymphocyte subset may be a cause of de-creased percentage of CD4^+ T lymphocyte subset. Thisinduces the increased ratio of CD4^+/CD8^+.展开更多
Objective: To study the immunological mechanisms ofCondyloma acuminata(CA) through investigating Tlymphocyte subset levels and cytokine profile in theperipheral blood of patients with CondylomaAcuminata. Methods: Tric...Objective: To study the immunological mechanisms ofCondyloma acuminata(CA) through investigating Tlymphocyte subset levels and cytokine profile in theperipheral blood of patients with CondylomaAcuminata. Methods: Tricolor and bicolor immunofluorescentstaining antibody of cell surface antigen and intracel-lular IL-2, IL-4, IL-12, IFN-Y in CD4^+ and CD8^+ T-lymphocytes from 20 patients with CA were performedand followed by flow cytometry. Results: The number of CD3^+T, CD4^+T-lymphocytescells and CD4^+/CD8^+T cells ratio were significantlydecreased(P<0.01) in patients with CA Compared tocontrols, and IL-2, IL-12, IFN-γ production in CD4^+Tcells was decreased(P<0.01), IL-4 and IFN-γ produc-tion in CD4^+T cells was not significantly different (P>0.05), while IL-2 and IL-12 production in CD8^+Tc cellswas decreased (P<0.01), whereas IFN-γ and IL-4 pro-ducing in CD4^+T cells were of no significantlydifference(P>0.05). Conclusions: There was an imbalance of T lympho-cyte subsets, Th1/Th2 cytokines and Tc1/Tc2 in theperipheral blood of CA patients, which may play animportant role in the pathogenesis and progression ofCA.展开更多
The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is pr...The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is proposed and applied to model and forecast power load. Numerical example verifies that desirable accuracy of short term load forecasting can be achieved by using the SSTAR model.展开更多
文摘In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors.
基金supported by the National Natural Science Foundation of China(Grant No.82274034)the Peking University Medicine plus X Pilot Program-Platform Construction Project(Grant No.2024YXXLHPT004).
文摘Ovarian cancer remains a leading cause of gynecological cancer mortality1,and patients with advanced stage ovarian cancer frequently develop malignant ascites that foster immunosuppressive microenvironments and therapeutic resistance2,3.Although ascites have traditionally been considered detrimental,we report a paradoxical role in which they enhance the cytotoxicity ofγδT cells—a unique T cell subset that can be allogenically transferred for cancer treatment4,5—toward ovarian cancer.
基金Supported by the National Natural Science Foundation of China,No.82300857.
文摘BACKGROUND Patients with acute-on-chronic liver failure(ACLF)experience severe immune dysfunction.Liver transplantation(LT)significantly improves survival outcomes.However,the characteristics of peripheral blood lymphocyte subsets(PBLSs)in this patient population are not well defined,and the dynamics of immune reconstitution post-LT are insufficiently understood.AIM To characterize PBLSs in patients with ACLF prior to LT and to evaluate PBLS reconstitution after LT.METHODS Clinical data from patients undergoing LT in the Transplantation Center,The Third Xiangya Hospital from January 2022 to December 2023 were analyzed retrospectively.Our cohort comprised 44 patients with ACLF,16 patients with acute decompensation of cirrhosis,and 23 patients with compensated cirrhosis.Twenty healthy volunteers were included as controls.PBLSs were evaluated across all groups.The relationship between PBLSs and post-LT prognosis was assessed,and dynamic changes in PBLSs among patients with ACLF were analyzed at different time points.RESULTS Patients with ACLF exhibited a marked reduction in PBLSs compared with healthy volunteers.Natural killer(NK)cell counts were further reduced in patients with ACLF when compared with patients with compensated cirrhosis.PBLSs did not correlate with the etiology or severity of ACLF or with established liver failure scores.Following LT,a rapid restoration of NK cells and B cells was observed in patients with ACLF.However,the cluster of differentiation(CD)3+T cell and CD4+T cell counts decreased 14 days post-LT and subsequently returned to preoperative levels by day 21.CONCLUSION Patients with ACLF exhibited markedly reduced PBLSs,with decreased NK cells potentially linked to progression from compensated cirrhosis to liver failure.NK and B cell were rapidly restored after LT.
基金supported by the National Social Science Fund of China(No.20CZX048)。
文摘In modal logic,topological semantics is an intuitive and natural special case of neighbourhood semantics.This paper stems from the observation that the satisfaction relation of topological semantics applies to subset spaces which are more general than topological spaces.The minimal modal logic which is strongly sound and complete with respect to the class of subset spaces is found.Soundness and completeness results of some famous modal logics(e.g.S4,S5 and Tr)with respect to various important classes of subset spaces(eg intersection structures and complete fields of sets)are also proved.In the meantime,some known results,e.g.the soundness and completeness of Tr with respect to the class of discrete topological spaces,are proved directly using some modifications of the method of canonical mode1,without a detour via neighbourhood semantics or relational semantics.
文摘The stratospheric airship is affected by harsh conditions in the stratosphere environment.To ensure the safety of the airship,it is necessary to detect the material state of the airship envelope.Since digital image correlation possesses non-contact strain measurement ability,this paper explores the infuence of different shapes of the subset on measurement accuracy.Through the results,it is found that increasing the aspect ratio of subsets can improve the strain accuracy measured in the c-direction,and reducing the aspect ratio can improve the strain accuracy measured in the y-direction.This trend becomes more obvious as the strain increases.Based on this discovery,a subset adaptive algorithm is proposed.The feasibility of the algorithm is verified by experiments,and the precision of strain measurement can be effectively improved by adjusting the threshold value.Therefore,the algorithm can be utilized to increase the measurement accuracy in the larger strain direction without changing the size of the subset.
文摘This article constructs statistical selection procedures for exponential populations that may differ in only the threshold parameters. The scale parameters of the populations are assumed common and known. The independent samples drawn from the populations are taken to be of the same size. The best population is defined as the one associated with the largest threshold parameter. In case more than one population share the largest threshold, one of these is tagged at random and denoted the best. Two procedures are developed for choosing a subset of the populations having the property that the chosen subset contains the best population with a prescribed probability. One procedure is based on the sample minimum values drawn from the populations, and another is based on the sample means from the populations. An “Indifference Zone” (IZ) selection procedure is also developed based on the sample minimum values. The IZ procedure asserts that the population with the largest test statistic (e.g., the sample minimum) is the best population. With this approach, the sample size is chosen so as to guarantee that the probability of a correct selection is no less than a prescribed probability in the parameter region where the largest threshold is at least a prescribed amount larger than the remaining thresholds. Numerical examples are given, and the computer R-codes for all calculations are given in the Appendices.
基金Foundation item:the National Natural Science Foundation of China(No.52075101)the Natural Science Foundation of Guangdong Province(No.2017A030313265)Guangzhou Scientific Research Plan(No.201904010184)。
文摘Aimed at the problem of the low computational efficiency of the existing urethral-valve reliability analysis,an efficient reliability analysis method of the wireless energy-transmitting urethral-valve(WETUV)was proposed.The method is called FTA-AK-SS,based on the active learning Kriging(AK)model,subset simulation(SS)algorithm,and fault tree analysis(FTA).According to the principle of FTA,we established the fault tree model of the WETUV to determine its minimum cut set and bottom events.Then we defined the random variables affecting its reliability.The U learning function was used to selectively add the sample points of random variables to update the initial Kriging surrogate model.At the same time,combined with the SS algorithm,the reliability and sensitivity analyses of the WETUV were realized.The result shows that compared with the traditional Monte Carlo simulation and FTA-Kriging-SS methods,the proposed method significantly improves the calculation efficiency of the WETUV under the premise of ensuring calculation accuracy.The reliability of the WETUV is greatly affected by the rubber pad’s aging,the receiver coil’s corrosion,and the position deviation.This study can provide a new way to realize a high-efficiency reliability calculation and analysis for urethral valves.
基金Project supported by the National Natural Science Foundation of China(No.52278180)。
文摘The fatigue of heavy-haul railway bridges is considered a key concern due to high stress levels and cyclic loading.The evaluation of fatigue reliability is required to include factor correlations.A major challenge is presented by the construction of the cumulative distribution function(CDF)and the description of correlations between random variables.In this study,the copula function is used to analyze the fatigue failure probability of the Shuohuang heavy-haul railway bridge.A C-vine copula(CVC)-based joint probability density function(JPDF)is derived with eight correlated parameters.To enhance efficiency in small failure probability calculations,the subset simulation and most probable point(MPP)Monte Carlo importance sampling are introduced based on the Rosenblatt transform and C-vine model.Comparisons with traditional Monte Carlo methods confirm that high accuracy and efficiency are achieved.The results show that when parameter correlations are ignored,failure probability is underestimated,increasing safety risks in bridge assessments.
基金The National Natural Science Foundation of China(No.51036002,51076027)the Key Project of Ministry of Education of China(No.108060)
文摘In order to meet the requirements of combustion optimization for saving energy and reducing pollutant emission simultaneously,an immune cell subsets based multiobjective optimization algorithm（ICSMOA）is proposed.In the ICSMOA,the subset division operator and the immunological tolerance operation are defined.Preference can be easily addressed by using the subset division operator,and the distribution of the solutions can be guaranteed by the immunological tolerance operation.Using the ICSMOA,a group of Pareto optimal solutions can be obtained.However,by the traditional weighting method（WM）,only one solution can be obtained and it cannot be judged as Pareto optimal or not.In contrast to the solutions obtained by the repeatedly performed WM,the simulation results show that most solutions obtained by the ICSMOA are better than the solutions obtained by the WM.In addition,the Pareto front obtained by the ICSMOA is not as uniform as most classical multiobjective optimization algorithms.More optimal solutions which meet the preference set by the decision-maker can be obtained and they are very useful for industrial application.
文摘There are some limitations when we apply conventional methods to analyze the massive amounts of seismic data acquired with high-density spatial sampling since processors usually obtain the properties of raw data from common shot gathers or other datasets located at certain points or along lines. We propose a novel method in this paper to observe seismic data on time slices from spatial subsets. The composition of a spatial subset and the unique character of orthogonal or oblique subsets are described and pre-stack subsets are shown by 3D visualization. In seismic data processing, spatial subsets can be used for the following aspects： （1） to check the trace distribution uniformity and regularity; （2） to observe the main features of ground-roll and linear noise; （3） to find abnormal traces from slices of datasets; and （4） to QC the results of pre-stack noise attenuation. The field data application shows that seismic data analysis in spatial subsets is an effective method that may lead to a better discrimination among various wavefields and help us obtain more information.
基金The National Basic Research Program of China (973Program) (No.2003CB716102).
文摘A new method that uses a modified ordered subsets （MOS） algorithm to improve the convergence rate of space-alternating generalized expectation-maximization （SAGE） algorithm for positron emission tomography （PET） image reconstruction is proposed.In the MOS-SAGE algorithm,the number of projections and the access order of the subsets are modified in order to improve the quality of the reconstructed images and accelerate the convergence speed.The number of projections in a subset increases as follows：2,4,8,16,32 and 64.This sequence means that the high frequency component is recovered first and the low frequency component is recovered in the succeeding iteration steps.In addition,the neighboring subsets are separated as much as possible so that the correlation of projections can be decreased and the convergences can be speeded up.The application of the proposed method to simulated and real images shows that the MOS-SAGE algorithm has better performance than the SAGE algorithm and the OSEM algorithm in convergence and image quality.
基金Supported by National Natural Scientif ic Foundation: 30772832
文摘Objective To compare effects of combined acupuncture and general anesthesia （CAGA） and general anesthesia （GA） on immune function in patients of laparoscopic cholecystectomy （LC） in peri-operative period. Methods Thirty-nine cases undergoing LC were randomly divided into a CAGA group and a GA group. The CAGA group was treated with electroacupuncture at Hegu （合谷- LI 4）, Neiguan （内关PC 6）, Zusanli （足三里ST 36） and Yanglingquan （阳陵泉 GB 34） for 15-30 minutes followed by the general anesthesia, and the continuous electroacupuncture stimulation was given till the operation finished. The GA group was treated with simple general anesthesia. Changes of T cell subsets, tumor necrosis factor-alpha （TNF-α） and interleukin-6 （IL-6） were observed before anesthesia induction, and 2 hours, 1st and 3 rd day after operation, and the adverse reaction after operation was recorded. Results At 2 hours after operation, the percentages of CD3 and CDs in both groups were significantly lower than those before anesthesia induction （all P〈0.05）, and the percentage of CD4 in the GA group decreased significantly （P〈0.05）, while the percentage of CD： did not significantly change and CD4/CD8 increased significantly in the CAGA group （P〈0.05）. At 3 days after operation, the level of TNF-α in the ACGA group decreased significantly as compared with that before anesthesia induction （P〈0.05）. The cases with nausea after operation in the CAGA group were significantly less than those in the GA group （P〈0.05）. Conclusion Acupuncture combined with general anesthesia has a little effect on immune function in patients of LC with less adverse reactions.
文摘Objective: To study the expression of Fas and Bcl-2proteins on T lymphocyte subsets in the peripheralblood of relapsing patients with condyloma acuminatum(CA) and healthy controls. Methods: Flow cytometry (permeabization andstaining procedure with conjugated antibodies) wasused. Results: We observed that the expression of Fasprotein on CD4^+ T lymphocyte subset of CA patientswas significantly higher than that of healthy controls(P<0.01). Conclusions: Increased expression of Fas proteinon CD4^+ T lymphocyte subset may be a cause of de-creased percentage of CD4^+ T lymphocyte subset. Thisinduces the increased ratio of CD4^+/CD8^+.
文摘Objective: To study the immunological mechanisms ofCondyloma acuminata(CA) through investigating Tlymphocyte subset levels and cytokine profile in theperipheral blood of patients with CondylomaAcuminata. Methods: Tricolor and bicolor immunofluorescentstaining antibody of cell surface antigen and intracel-lular IL-2, IL-4, IL-12, IFN-Y in CD4^+ and CD8^+ T-lymphocytes from 20 patients with CA were performedand followed by flow cytometry. Results: The number of CD3^+T, CD4^+T-lymphocytescells and CD4^+/CD8^+T cells ratio were significantlydecreased(P<0.01) in patients with CA Compared tocontrols, and IL-2, IL-12, IFN-γ production in CD4^+Tcells was decreased(P<0.01), IL-4 and IFN-γ produc-tion in CD4^+T cells was not significantly different (P>0.05), while IL-2 and IL-12 production in CD8^+Tc cellswas decreased (P<0.01), whereas IFN-γ and IL-4 pro-ducing in CD4^+T cells were of no significantlydifference(P>0.05). Conclusions: There was an imbalance of T lympho-cyte subsets, Th1/Th2 cytokines and Tc1/Tc2 in theperipheral blood of CA patients, which may play animportant role in the pathogenesis and progression ofCA.
文摘The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is proposed and applied to model and forecast power load. Numerical example verifies that desirable accuracy of short term load forecasting can be achieved by using the SSTAR model.
