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Mental emotional disorder is a predictor of stroke incidence in adults:Ten year results of the Bogor Cohort Study on Non-Communicable Disease Risk Factors in Indonesia 被引量:1
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作者 Woro Riyadina Alifa Syamantha Putri +2 位作者 Sulistyowati Tuminah Ika Suswanti Yuda Turana 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第8期351-357,共7页
Objective:To determine the stroke predictors for the 10-year of follow-up in Bogor City,Indonesia.Methods:The prospective study analyzed the data of 4445 stroke-free subjects aged 25 years and above that was part of&q... Objective:To determine the stroke predictors for the 10-year of follow-up in Bogor City,Indonesia.Methods:The prospective study analyzed the data of 4445 stroke-free subjects aged 25 years and above that was part of"the Bogor Cohort Study on Non-Communicable Disease Risk Factors".Data were collected by interview method with structured questionnaires,physical measurements three times a year,and laboratory examination every two years during a 10-year follow-up(2011-2021,without examination in 2020).The incidence of stroke is based on anamnesis results and examination by a neurologist.Other stroke predictor variables include characteristics,biological conditions,and risk behavior.We analysed 4445 stroke-free samples with Cox proportional hazard regression test.Results:During the 10-year observation,stroke incidence was 440 person-years per 100000 population(95%CI 370-530).During the follow-up of ten years,the main predictor of stroke was mental-emotional disorders with HR 4.2(95%CI 2.8-6.3)after adjustment by age,hypertension,obesity,abdominal obesity,and high LDL-cholesterol levels.Conclusions:Mental-emotional disorders are the strongest predictor of stroke incidence.Hence,psychological factors must be controlled in a stroke prevention program. 展开更多
关键词 ADULT COHORT Mental-emotional disorder Stroke predictor
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Predictors of Abnormal Vaginal Discharge among Women of Reproductive Age in Southeast Nigeria
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作者 Jideuma Egwim Victor Dike +5 位作者 Hope Igbonagwam Nkechinyere Oke Uzoma Amajo Akuchi Okafor Angela Izegbune Ijedimma Okafor 《International Journal of Clinical Medicine》 CAS 2024年第7期240-256,共17页
Background: An abnormal vaginal discharge is a common complaint among women of reproductive age, and it can indicate serious conditions like pelvic inflammatory disease and cervical cancer. This study aimed to assess ... Background: An abnormal vaginal discharge is a common complaint among women of reproductive age, and it can indicate serious conditions like pelvic inflammatory disease and cervical cancer. This study aimed to assess the predictors of abnormal vaginal discharge in women of reproductive age group in Imo State, Southeast Nigeria. Methods: A cross-sectional study was conducted among 368 women of reproductive age group attending the clinic at Federal University Teaching Hospital Owerri, in Imo State, Nigeria. Respondents were recruited using a systematic sampling technique. Data were collected using a pre-tested interviewer-administered questionnaire. Multivariable analysis was performed to determine predictors of abnormal vaginal discharge. Statistical significance was set at p Results: The mean age of the respondents was 30 ±  4.5 years. Predictors of abnormal vaginal discharge were: age 36 - 45 years (OR: 4.5;95% C.I: 1.023 - 8.967, p = 0.041), being a student (OR: 2.4: 95% C.I: 1.496 - 7.336, p = 0.003), use of oral contraceptives (OR: 3.4;95% C.I: 1.068 - 6.932, p = 0.010), use of water cistern (OR: 4.7;C.I: 1.654 - 5.210, p = 0.028) anal hygiene practices (OR: 2.7;95% C.I: 1.142 - 4.809, p Conclusion: These findings suggest that targeted sexual and reproductive health interventions should be provided to reduce the risk of abnormal vaginal discharge in women of reproductive age group. 展开更多
关键词 predictorS ABNORMAL VAGINAL DISCHARGE
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Echocardiographic predictors and associated outcomes of multiple vegetations in infective endocarditis:A pilot study
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作者 Ajay Kumar Mishra Kannu Bansal +6 位作者 Ibragim Al-Seykal Pradnya B Bhattad Anu Anna George Anil Jha Nitish Sharma Jennifer Sargent Mark J Kranis 《World Journal of Cardiology》 2024年第6期318-328,共11页
BACKGROUND Infective endocarditis(IE)is a life-threatening infection with an annual mortality of 40%.Embolic events reported in up to 80%of patients.Vegetations of>10 mm size are associated with increased embolic e... BACKGROUND Infective endocarditis(IE)is a life-threatening infection with an annual mortality of 40%.Embolic events reported in up to 80%of patients.Vegetations of>10 mm size are associated with increased embolic events and poor prognosis.There is a paucity of literature on the association of multiple vegetations with outcome.AIM To study the echocardiographic(ECHO)features and outcomes associated with the presence of multiple vegetations.METHODS In this retrospective,single-center,cohort study patients diagnosed with IE were recruited from June 2017 to June 2019.A total of 84 patients were diagnosed to have IE,of whom 67 with vegetation were identified.Baseline demographic,clinical,laboratory,and ECHO parameters were reviewed.Outcomes that were studied included recurrent admission,embolic phenomenon,and mortality.RESULTS Twenty-three(34%)patients were noted to have multiple vegetations,13(56.5%)were male and 10(43.5%)were female.The mean age of these patients was 50.Eight(35%)had a prior episode of IE.ECHO features of moderate to severe valvular regurgitation[odds ratio(OR)=4],presence of pacemaker lead(OR=4.8),impaired left ventricle(LV)relaxation(OR=4),and elevated pulmonary artery systolic pressure(PASP)(OR=2.2)are associated with higher odds of multiple vegetations.Of these moderate to severe valvular regurgitation(P=0.028),pacemaker lead(P=0.039)and impaired relaxation(P=0.028)were statistically significant.These patients were noted to have an increased association of recurrent admissions(OR=3.6),recurrent bacteremia(OR=2.4),embolic phenomenon(OR=2.5),intensive care unit stay(OR=2.8),hypotension(OR=2.1),surgical intervention(OR=2.8)and device removal(OR=4.8).Of this device removal(P=0.039)and recurrent admissions(P=0.017)were statistically significant.CONCLUSION This study highlights the associations of ECHO predictors and outcomes in patients with IE having multiple vegetations.ECHO features of moderate to severe regurgitation,presence of pacemaker lead,impaired LV relaxation,and elevated PASP and outcomes including recurrent admissions and device removal were found to be associated with multiple vegetations. 展开更多
关键词 ENDOCARDITIS ECHOCARDIOGRAPHY VEGETATIONS predictorS OUTCOME
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Predictors of Fatal Outcome in Hospitalised Adult Patients with Acute Kidney Injury at Two Tertiary Hospitals in Sub-Saharan Africa
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作者 Denis Georges Teuwafeu Fombo Enjeh Jabbossung +4 位作者 Maimouna Mahamat Eric Aristide Nono Tomta Mbapah Leslie Tasha Francois Kaze Folefack Gloria Ashuntantang 《Open Journal of Nephrology》 2024年第1期86-103,共18页
Introduction: Data on mortality in acute kidney injury (AKI) derives from high-income countries where AKI is hospital-acquired and occurs in elderly patients with a high burden of cardiovascular disease. In sub-Sahara... Introduction: Data on mortality in acute kidney injury (AKI) derives from high-income countries where AKI is hospital-acquired and occurs in elderly patients with a high burden of cardiovascular disease. In sub-Saharan Africa (SSA), AKI is community-acquired occurring in healthy young adults. We aimed to identify predictors of fatal outcomes in patients with AKI in two tertiary hospitals in Cameroon. Methods: Medical records of adults with confirmed AKI, from January 2018 to March 2020 were retrieved. The outcomes of interest were in-hospital deaths and presumed causes of death. We used multiple logistic regressions modeling to identify predictors of death. The study was approved by the ethics boards of both hospitals. Values were considered significant for a p-value of 0.05. Results: We included 285 patient records (37.2% females). The mean (SD) age was 50.1 (19.0) years. Hypertension (n = 97, 34.0%), organ failure (n = 88, 30.9%), and diabetes (n = 60, 21.1%) were the main comorbidities. The majority of patients had community-acquired AKI (78.6%, n = 224), were KDIGO stage 3 (88.8%, n = 253), and needed dialysis (52.6%, n = 150). Up to 16.7% (n = 25) did not receive what was needed. The in-hospital mortality rate was 29.1% (n = 83). Lack of access to dialysis (OR = 27.8;CI: 5.2 - 149.3, p = 0.001), hypotension (OR = 11.8;CI: 1.3 - 24.8;p = 0.001) and ICU admission (OR = 5.7;CI: 1.3 - 24.8, p = 0.001) were predictors of mortality. The presence of co-morbidities or underlying diseases (n = 46, 55%) were the main causes of death. Conclusions: In-hospital AKI mortality is high, as in other low- and middle-income economies. Lack of access to dialysis and the severity of the underlying illness are major predictors of death. 展开更多
关键词 predictorS Fatal Outcome Acute Kidney Injury Tertiary Hospital
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Predictors of portal vein thrombosis after splenectomy in patients with cirrhosis
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作者 Ting Li Li-Li Wang +4 位作者 Ya-Ping Li Jian Gan Xi-Sheng Wei Xiao-Rong Mao Jun-Feng Li 《World Journal of Hepatology》 2024年第2期241-250,共10页
BACKGROUND Portal vein thrombosis(PVT)is a commonthsn complication after splenectomy in patients with cirrhosis.However,the predictors of postoperative PVT are not known.AIM To investigate the predictors of PVT after ... BACKGROUND Portal vein thrombosis(PVT)is a commonthsn complication after splenectomy in patients with cirrhosis.However,the predictors of postoperative PVT are not known.AIM To investigate the predictors of PVT after splenectomy in patient with cirrhosis.METHODS A total of 45 patients with cirrhosis who underwent splenectomy were consecutively enrolled from January 2017 to December 2018.The incidence of PVT at 1 months,3 months,and 12 months after splenectomy in patients with cirrhosis was observed.The hematological indicators,biochemical and coagulation parameters,and imaging features were recorded at baseline and at each observation point.The univariable,multivariable,receiver operating characteristic curve and timedependent curve analyses were performed.RESULTS The cumulative incidence of PVT was 40.0%,46.6%,and 48.9%at 1 months,3 months,and 12 months after splenectomy.Multivariable analysis showed that portal vein diameter(PVD)≥14.5 mm and monthsdel end-stage liver disease(MELD)score>10 were independent predictors of PVT at 1 months,3 months,and 12 months after splenectomy(P<0.05).Time-dependent curve showed that the cumulative incidence of PVT was significantly different between patients with MELD score≤10 and>10(P<0.05).In addition,the cumulative incidence of PVT in the PVD≥14.5 mm group was significantly higher than that in the PVD<14.5 mm group(P<0.05).CONCLUSION Wider PVD and MELD score>10 were independent predictors of PVT at 1 months,3 months,and 12 months after splenectomy in patient with cirrhosis. 展开更多
关键词 CIRRHOSIS SPLENECTOMY Portal vein thrombosis predictorS
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Rates, predictors, and causes of readmission after transcatheter aortic valve replacement in patients with chronic kidney disease
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作者 Taha Teaima Gianfranco Bittar Carlini +5 位作者 Rohan A Gajjar Imran Aziz Sami J Shoura Abdul-Rahim Shilbayeh Naim Battikh Tareq Alyousef 《World Journal of Cardiology》 2024年第7期402-411,共10页
BACKGROUND Transcatheter aortic valve replacement(TAVR)is a revolutionary procedure for severe aortic stenosis.The coexistence of chronic kidney disease(CKD)and TAVR introduces a challenge that significantly impacts p... BACKGROUND Transcatheter aortic valve replacement(TAVR)is a revolutionary procedure for severe aortic stenosis.The coexistence of chronic kidney disease(CKD)and TAVR introduces a challenge that significantly impacts patient outcomes.AIM To define readmission rates,predictors,and causes after TAVR procedure in CKD stage 1-4 patients.METHODS We used the national readmission database 2018 and 2020 to look into readmission rates,causes and predictors after TAVR procedure in patients with CKD stage 1-4.RESULTS Out of 24758 who underwent TAVR and had CKD,7892(32.4%)patients were readmitted within 90 days,and had higher adjusted odds of being females(adjusted odds ratio:1.17,95%CI:1.02-1.31,P=0.02)with longer length of hospital stay>6 days,and more comorbidities including but not limited to diabetes mellitus,anemia,and congestive heart failure(CHF).CONCLUSION Most common causes of readmission included CHF(18.0%),sepsis,and complete atrioventricular block.Controlling readmission predictors with very close followup is warranted to prevent such high rate of readmission. 展开更多
关键词 Chronic kidney disease Transcatheter aortic valve replacement READMISSION predictorS Rates
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Heterogeneously elevated branched-chain/aromatic amino acids among new-onset type-2 diabetes mellitus patients are potentially skewed diabetes predictors
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作者 Min Wang Yang Ou +7 位作者 Xiang-Lian Yuan Xiu-Fang Zhu Ben Niu Zhuang Kang Bing Zhang Anwar Ahmed Guo-Qiang Xing Heng Su 《World Journal of Diabetes》 SCIE 2024年第1期53-71,共19页
BACKGROUND The lack of specific predictors for type-2 diabetes mellitus(T2DM)severely impacts early intervention/prevention efforts.Elevated branched-chain amino acids(BCAAs:Isoleucine,leucine,valine)and aromatic amin... BACKGROUND The lack of specific predictors for type-2 diabetes mellitus(T2DM)severely impacts early intervention/prevention efforts.Elevated branched-chain amino acids(BCAAs:Isoleucine,leucine,valine)and aromatic amino acids(AAAs:Tyrosine,tryptophan,phenylalanine)show high sensitivity and specificity in predicting diabetes in animals and predict T2DM 10-19 years before T2DM onset in clinical studies.However,improvement is needed to support its clinical utility.AIM To evaluate the effects of body mass index(BMI)and sex on BCAAs/AAAs in new-onset T2DM individuals with varying body weight.METHODS Ninety-seven new-onset T2DM patients(<12 mo)differing in BMI[normal weight(NW),n=33,BMI=22.23±1.60;overweight,n=42,BMI=25.9±1.07;obesity(OB),n=22,BMI=31.23±2.31]from the First People’s Hospital of Yunnan Province,Kunming,China,were studied.One-way and 2-way ANOVAs were conducted to determine the effects of BMI and sex on BCAAs/AAAs.RESULTS Fasting serum AAAs,BCAAs,glutamate,and alanine were greater and high-density lipoprotein(HDL)was lower(P<0.05,each)in OB-T2DM patients than in NW-T2DM patients,especially in male OB-T2DM patients.Arginine,histidine,leucine,methionine,and lysine were greater in male patients than in female patients.Moreover,histidine,alanine,glutamate,lysine,valine,methionine,leucine,isoleucine,tyrosine,phenylalanine,and tryptophan were significantly correlated with abdominal adiposity,body weight and BMI,whereas isoleucine,leucine and phenylalanine were negatively correlated with HDL.CONCLUSION Heterogeneously elevated amino acids,especially BCAAs/AAAs,across new-onset T2DM patients in differing BMI categories revealed a potentially skewed prediction of T2DM development.The higher BCAA/AAA levels in obese T2DM patients would support T2DM prediction in obese individuals,whereas the lower levels of BCAAs/AAAs in NW-T2DM individuals may underestimate T2DM risk in NW individuals.This potentially skewed T2DM prediction should be considered when BCAAs/AAAs are to be used as the T2DM predictor. 展开更多
关键词 Hyperaminoacidemia Branched-chain/aromatic amino acids New-onset type-2 diabetes predictor Obesity SEX
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Depression&Anxiety Among Women in Northern Kenya:Sociodemographic Predictors
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作者 Gladys Kabura Mwangi 《Psychology Research》 2024年第2期57-63,共7页
This article documents socio-demographic predictors of anxiety and depression among Maasai women in resource poor settings in Northern Kenya.These findings emerged from the findings of a dissertation research that aim... This article documents socio-demographic predictors of anxiety and depression among Maasai women in resource poor settings in Northern Kenya.These findings emerged from the findings of a dissertation research that aimed to establish the treatment effectiveness of an eclectic model of psychoeducation(PE)in treating depressive and anxiety symptoms among the women.The study adopted a quasi-experimental research design which had an experimental group(EG)and control group(CG).The population for the study was 686 female members of Conservation Enterprise Groups(CEG)in Laikipia County,from which a sample of 200 were recruited for the study(EG,n=100 and CG,n=100),at 80%power and 30%effective size.The Beck’s Depression Inventory(BDI)and Beck’s Anxiety Inventory(BAI)tools were used to assess the symptoms of depression and anxiety,respectively.The PE was provided as an intervention treatment to the EG at the middle and end of the study,after which the respondents were tested for symptoms of depression.The study established the prevalence of depression as 26.7%and 31.3%for anxiety and disorders,among women in the region.Data was analyzed using SPSS Version 21.0. 展开更多
关键词 SOCIODEMOGRAPHIC ANXIETY DEPRESSION predictorS Maasai women Northern Kenya
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Predictors of stricture after endoscopic submucosal dissection of the esophagus and steroids application
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作者 Qing-Xia Wang Yuan Ding +2 位作者 Qi-Liu Qian Yin-Nan Zhu Rui-Hua Shi 《World Journal of Gastrointestinal Endoscopy》 2024年第9期509-518,共10页
BACKGROUND Endoscopic submucosal dissection(ESD)is a reliable method to resect early esophageal cancer.Esophageal stricture is one of the major complications after ESD of the esophagus.Steroid prophylaxis for esophage... BACKGROUND Endoscopic submucosal dissection(ESD)is a reliable method to resect early esophageal cancer.Esophageal stricture is one of the major complications after ESD of the esophagus.Steroid prophylaxis for esophageal strictures,particularly local injection of triamcinolone acetonide(TA),is a relatively effective method to prevent esophageal strictures.However,even with steroid prophylaxis,stenosis still occurs in up to 45%of patients.Predicting the risk of stenosis formation after local TA injection would enable additional interventions in risky patients.AIM To identify the predictors of esophageal strictures after steroids application.METHODS Patients who underwent esophageal ESD and steroid prophylaxis and who were comprehensively assessed for lesion-and ESD-related factors at Southeast University Affiliated Zhongda Hospital between February 2018 and March 2023 were included in the study.The univariate and multivariate regression analyses were conducted to identify the predictors of stricture among patients undergoing steroid prophylaxis.RESULTS A total of 120 patients were included in the analysis.In the oral prednisone and oral prednisone combined with local tretinoin injection groups,the stenosis rates were 44/53(83.0%)and 56/67(83.6%),respectively.Among them,univariate analysis showed that the lesion circumference(P=0.01)and submucosal injection solution(P=0.04)showed significant correlation with the risk of stenosis formation.Logistic regression analyses were then performed using predictors that were significant in the univariate analyses and combined with known predictors from previous reports,such as additional chemoradiotherapy and tumor location.We identified a lesion circumference<5/6(OR=0.19;P=0.02)and submucosal injection of sodium hyaluronate(OR=0.15;P=0.03)as independent predictors of on esophageal stricture formation.CONCLUSION Steroid prophylaxis effectively prevents stenosis.Moreover,the lesion circumference and submucosal injection of sodium hyaluronate were independent predictors of esophageal strictures.Additional interventions should be considered in high-risk patients. 展开更多
关键词 Endoscopic submucosal dissection Esophageal stricture Oral steroids Triamcinolone acetonide predictorS
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Time to recovery from severe pneumonia and its predictors among pediatric patients admitted in Mizan-Tepi University Teaching Hospital,South West Ethiopia,2022
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作者 Belete Fenta Kebede Aynalem Yetwale Hiwot +2 位作者 Tsegaw Biyazin Tesfa Yalemtsehay Dagnaw Genie Nigatu Dessalegn Mulu 《Frontiers of Nursing》 2024年第3期343-353,共11页
Objective:Despite trials and programs for the prevention of childhood mortality due to pneumonia,Ethiopia is among the top five countries with the highest number of deaths due to pneumonia.Although the prevalence of p... Objective:Despite trials and programs for the prevention of childhood mortality due to pneumonia,Ethiopia is among the top five countries with the highest number of deaths due to pneumonia.Although the prevalence of pneumonia has increased in the abovementioned trials,little is known about the recovery time from severe pneumonia and its predictors in the study area.Therefore,this study aimed to assess the time to recovery from severe pneumonia and its predictors among pediatric patients admitted to Mizan-Tepi University Teaching Hospital,Ethiopia,in 2022.Methods:A total of 591 children admitted for severe pneumonia were selected using simple random sampling.Data were entered into Epi-data version 4.4.2.1 and expor ted to STATA version 14 for analysis,and the assumptions of Cox propor tional hazard models and goodness of fit were assessed through Shoenfeld residual and Cox-Snell residual,respectively.Bivariate and multivariable Cox regression models were used to identify the predictors of mor tality.Results:This study revealed that 91.54%(95%confidence interval[CI]:89.00–93.53)of participants recovered with an incidence rate of 24.10(95%CI:22.15–26.21)per 100 person-day–observations.The hmedian recovery time of children was 4 days(95%CI:2–6).Children who were not exclusively breastfed(AHR=1.3;95%CI:1.03–1.66),who had a history of inability to suck/feed(AHR=0.81;95%CI:0.65–0.99)were independent predictors of the time to recovery.Conclusions:Children with severe pneumonia who had not exclusively breastfed and who had a history of inability to suck/feed were independent predictors of time to recovery.Therefore,all stakeholders and concerned health care providers should focus more on early diagnosis and management and hasten early recovery based on the identified factors. 展开更多
关键词 Mizan-Tepi University Teaching Hospital pediatric patients predictorS severe pneumonia Southwest Ethiopia time to recovery
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A Full Predictor-Corrector Finite Element Method for the One-Dimensional Heat Equation with Time-Dependent Singularities
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作者 Jake L. Nkeck 《Journal of Applied Mathematics and Physics》 2024年第4期1364-1382,共19页
The energy norm convergence rate of the finite element solution of the heat equation is reduced by the time-regularity of the exact solution. This paper presents an adaptive finite element treatment of time-dependent ... The energy norm convergence rate of the finite element solution of the heat equation is reduced by the time-regularity of the exact solution. This paper presents an adaptive finite element treatment of time-dependent singularities on the one-dimensional heat equation. The method is based on a Fourier decomposition of the solution and an extraction formula of the coefficients of the singularities coupled with a predictor-corrector algorithm. The method recovers the optimal convergence rate of the finite element method on a quasi-uniform mesh refinement. Numerical results are carried out to show the efficiency of the method. 展开更多
关键词 SINGULARITIES Finite Element Methods Heat Equation predictor-Corrector Algorithm
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基于Fuzzy-Smith补偿控制的煤泥水自动加药系统仿真研究 被引量:5
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作者 王光辉 匡亚莉 +1 位作者 王传真 申迎松 《工矿自动化》 北大核心 2012年第9期39-42,共4页
分析了煤泥水系统的絮凝沉降过程,推导出絮凝剂、凝聚剂加药量与溢流浓度之间的传递函数,计算得两个传递函数的惯性滞后时间与纯滞后时间比值均远大于0.3,说明煤泥水处理过程是一个大时滞性系统;介绍了Fuzzy-Smith补偿控制基本原理,构... 分析了煤泥水系统的絮凝沉降过程,推导出絮凝剂、凝聚剂加药量与溢流浓度之间的传递函数,计算得两个传递函数的惯性滞后时间与纯滞后时间比值均远大于0.3,说明煤泥水处理过程是一个大时滞性系统;介绍了Fuzzy-Smith补偿控制基本原理,构建了基于Fuzzy-Smith补偿控制的煤泥水自动加药系统的仿真结构。仿真结果表明,Fuzzy-Smith补偿控制策略较传统PID控制策略具有更快的系统响应速度,较好地解决了煤泥水处理过程的大时滞性问题。 展开更多
关键词 煤泥水 自动加药 絮凝沉降 絮凝剂 凝聚剂 大时滞性 fuzzy-smith补偿控制
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The Chebyshev spectral element method using staggered predictor and corrector for elastic wave simulations 被引量:3
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作者 车承轩 王秀明 林伟军 《Applied Geophysics》 SCIE CSCD 2010年第2期174-184,195,共12页
Based on strong and weak forms of elastic wave equations, a Chebyshev spectral element method (SEM) using the Galerkin variational principle is developed by discretizing the wave equation in the spatial and time dom... Based on strong and weak forms of elastic wave equations, a Chebyshev spectral element method (SEM) using the Galerkin variational principle is developed by discretizing the wave equation in the spatial and time domains and introducing the preconditioned conjugate gradient (PCG)-element by element (EBE) method in the spatial domain and the staggered predictor/corrector method in the time domain. The accuracy of our proposed method is verified by comparing it with a finite-difference method (FDM) for a homogeneous solid medium and a double layered solid medium with an inclined interface. The modeling results using the two methods are in good agreement with each other. Meanwhile, to show the algorithm capability, the suggested method is used to simulate the wave propagation in a layered medium with a topographic traction free surface. By introducing the EBE algorithm with an optimized tensor product technique, the proposed SEM is especially suitable for numerical simulation of wave propagations in complex models with irregularly free surfaces at a fast convergence rate, while keeping the advantage of the finite element method. 展开更多
关键词 Chebyshev spectral element element by element predictor/corrector algorithm
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用Polymorph Predictor方法模拟TATB的晶体结构 被引量:3
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作者 张朝阳 舒远杰 +2 位作者 赵晓东 李海波 李金山 《含能材料》 EI CAS CSCD 2004年第1期48-51,共4页
采用PolymorphPredictor方法对TATB的晶体结构进行模拟的结果是:P-1,a=9.01 ,b=9.01 ,c=6.01 ,α=90.01°,β=90.01°,γ=120.00°,ρ=2.03g·cm-3,并得到XRD谱图(2θ=11.5、29.5处有强峰),结果与实验值比较接近。
关键词 Polymorphpredictor方法 TATB 晶体结构 高能钝感炸药
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Fuzzy-Smith控制器在pH值控制中的应用 被引量:4
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作者 李涛 蒲鸿春 +1 位作者 冯宇 邱剑 《仪器仪表与分析监测》 2009年第2期10-11,共2页
针对油田污水pH处理系统具有的大惯性、纯滞后、非线性等特点,文章采用模糊控制和Sm ith预估控制相结合的控制方法。仿真结果表明此种控制方法动态性能良好,且具有较强的鲁棒性和抗干扰能力。
关键词 PH值 模糊控制 SMITH预估控制 fuzzy-smith控制 仿真
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积分时滞系统的Fuzzy-Smith预估器的研究 被引量:1
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作者 唐彪 段小刚 +1 位作者 沈平 李涵雄 《控制工程》 CSCD 北大核心 2010年第S3期69-72,共4页
针时积分时滞系统,基于PID的Smith预估器需要被控对象的精确数学模型,对于实际工业过程中难以建模和参数变化的被控对象,其鲁棒性差,控制性能也往往达不到期望的效果。模糊PID控制器因其鲁棒性强的优点,在工业界得到了广泛应用,但目前... 针时积分时滞系统,基于PID的Smith预估器需要被控对象的精确数学模型,对于实际工业过程中难以建模和参数变化的被控对象,其鲁棒性差,控制性能也往往达不到期望的效果。模糊PID控制器因其鲁棒性强的优点,在工业界得到了广泛应用,但目前仍然缺乏充分的解析理论分析。针对这些现状,将可解析的模糊PID控制器引入Smith预估器以提高其鲁棒性,并从理论上证明了这种Fuzzy-Smith预估器的鲁棒性优于传统的基于PID控制器的Smith预估器。基于二阶积分时滞系统,结合模糊PID的滑模特性,采用李亚普洛夫稳定性理论,在理论上分析和证明了由于模糊PID控制器中非线性项的存在从而能补偿更多的不确定性,因此其鲁棒性更好。最后的仿真结果进一步证明了这点。 展开更多
关键词 积分时滞系统 fuzzy-smith预估器 模糊PID控制器 鲁棒性
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基于Fuzzy-Smith控制器的营养液pH值调控系统研究 被引量:7
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作者 李帅帅 李莉 +3 位作者 穆永航 王宏康 吴勇 SIGRIMIS N 《农业机械学报》 EI CAS CSCD 北大核心 2017年第S1期347-352,393,共7页
pH值的控制是水肥一体化营养液循环控制系统的重要环节,水肥控制过程中pH值在最优控制范围内有利于根系的发育以及多数矿物质的吸收。营养液调控过程中,由于循环管路以及酸液的缓慢扩散,使得pH值调节过程存在很大的时滞,传统PID难以取... pH值的控制是水肥一体化营养液循环控制系统的重要环节,水肥控制过程中pH值在最优控制范围内有利于根系的发育以及多数矿物质的吸收。营养液调控过程中,由于循环管路以及酸液的缓慢扩散,使得pH值调节过程存在很大的时滞,传统PID难以取得良好效果。本研究根据被控对象特点,建立了描述该过程的数学模型,设计开发了一套具有二次混肥特性的以MSP430单片机为主控的营养液pH值控制系统。由于参数自整定模糊PID不需要精确数学模型以及Smith预估可对纯滞后进行补偿的特点,开发的系统将参数自整定模糊PID控制引入Smith预估当中,既缓解了滞后时间对控制系统的影响,又对模型的不精确性进行了补偿。为了验证该算法以及系统的有效性和优越性,分别对PID、Fuzzy-Smith控制算法进行仿真测试,同时在不同灌溉量下进行性能试验。试验结果表明,在不同灌溉量下Fuzzy-Smith控制算法pH值的平均最大超调量为0.83%,营养液pH值从8.0调节为6.0的平均时间为157 s,优于常规PID控制的2.55%和189 s。 展开更多
关键词 P H值调控 fuzzy-smith控制 二次混肥 水肥一体化 灌溉
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Fuzzy-smith控制器在温度控制中的应用 被引量:4
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作者 王春亮 李茜 《自动化与仪表》 北大核心 2011年第12期41-43,共3页
废纸制浆过程中,由于加热过程存在滞后、蒸汽压力波动和进浆浓度的变化热分散使得温度控制效果受到影响。针对热分散系统的温度控制具有纯滞后和模型不确定的特性,提出了改进型Fuzzy-smith控制策略。仿真研究表明,该方案不仅能够进一步... 废纸制浆过程中,由于加热过程存在滞后、蒸汽压力波动和进浆浓度的变化热分散使得温度控制效果受到影响。针对热分散系统的温度控制具有纯滞后和模型不确定的特性,提出了改进型Fuzzy-smith控制策略。仿真研究表明,该方案不仅能够进一步克服纯滞后,而且具有较强的鲁棒性和较高的控制精度,在模型失配时亦能表现出良好的稳定性和鲁棒性。通过在某纸厂实际应用,取得了良好的控制效果。 展开更多
关键词 热分散 改进型fuzzy-smith 温度控制 PID控制器
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凸二次规划的Predictor-Corrector算法
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作者 郭田德 《曲阜师范大学学报(自然科学版)》 CAS 1995年第2期1-6,共6页
考虑凸二次规划问题,给出了一个新的算法。
关键词 凸二次规划 P-C算法 线性规划 内点算法
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Characteristics and predictors of gastric cancer after Helicobacter pylori eradication 被引量:29
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作者 Satoki Shichijo Yoshihiro Hirata 《World Journal of Gastroenterology》 SCIE CAS 2018年第20期2163-2172,共10页
Helicobacter pylori(H. pylori) eradication can reduce gastric cancer. However, gastric cancer still develops after eradication, and cases who received eradication therapy are increasing. In this study, we have reviewe... Helicobacter pylori(H. pylori) eradication can reduce gastric cancer. However, gastric cancer still develops after eradication, and cases who received eradication therapy are increasing. In this study, we have reviewed the characteristics and predictors of primary gastric cancer developing after H. pylori eradication. In terms of the characteristics, endoscopic, histologic, and molecular characteristics are reported. Endoscopically, gastric cancer after eradication is often depressedtype and shows a gastritis-like appearance, which sometimes makes the diagnosis difficult. Histologically, most gastric cancer after eradication is intestinal type, and non-neoplastic epithelium, also called epithelium with low-grade atypia, is frequently seen over the tumor, which is presumably the cause of the endoscopic gastritis-like appearance. As for molecular characteristics, some markers, such as Ki67, MUC2, and Wnt5a expression, are lower in cancer from patients in whom H. pylori has been eradicated. In terms of predictors, several Japanese studies have reported that severe endoscopic atrophy at eradication is a risk factor for gastric cancer development. Histologic intestinal metaplasia, especially in the corpus, and long-term use of proton pump inhibitors, are also reported as risk factors for gastric cancer after H. pylori eradication. These studies on the characteristics and predictors of gastric cancer development will become the cornerstone for establishing a novel surveillance program based on the gastric cancer risk stratification specific to H. pylori-eradicated patients. 展开更多
关键词 GASTRIC cancer ERADICATION characteristic HELICOBACTER PYLORI predictor
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