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Predictive value of the systemic immune inflammation index in recurrence of atrial fibrillation after radiofrequency catheter ablation
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作者 Alexander E Berezin 《World Journal of Cardiology》 2025年第1期22-27,共6页
The recurrence of atrial fibrillation(AF)in patients after successful radiofrequency catheter ablation(RFCA)appears to be an unresolved clinical issue and needs to be clearly elucidated.There are many factors associat... The recurrence of atrial fibrillation(AF)in patients after successful radiofrequency catheter ablation(RFCA)appears to be an unresolved clinical issue and needs to be clearly elucidated.There are many factors associated with AF recurrence,such as duration of AF,male sex,concomitant heart failure,hemodynamic parameters,chronic obstructive pulmonary disease,hypertension,obstructive sleep apnea,hyperthyroidism,smoking and obesity.However,the inflammatory changes are strongly associated with electrical and structural cardiac remodeling,cardiac damage,myocardial fibrotic changes,microvascular dysfunction and altered reparative response.In this context,biomarkers reflecting the different stages of AF pathogenesis deserve thorough investigation.The authors of the retrospective study revealed that one-year recurrence rate of non-valvular AF in the high systemic immune inflammation(SII)index group was significantly increased compared to that of the low SII index group and provided additional predictive value to the APPLE.Furthermore,the authors suggest that this biomarker may help physicians to optimize the selection of AF patients and to develop a personalized treatment approach.In conclusion,the SII index may serve as a valuable indicator of recurrent AF in patients after RFCA and may be a biomarker with plausible predictive value for poor clinical outcomes. 展开更多
关键词 Systemic immune inflammation index Recurrent atrial fibrillation Radiofrequency catheter ablation Biomarkers APPLE score Prediction
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Structured Multi-Head Attention Stock Index Prediction Method Based Adaptive Public Opinion Sentiment Vector
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作者 Cheng Zhao Zhe Peng +2 位作者 Xuefeng Lan Yuefeng Cen Zuxin Wang 《Computers, Materials & Continua》 SCIE EI 2024年第1期1503-1523,共21页
The present study examines the impact of short-term public opinion sentiment on the secondary market,with a focus on the potential for such sentiment to cause dramatic stock price fluctuations and increase investment ... The present study examines the impact of short-term public opinion sentiment on the secondary market,with a focus on the potential for such sentiment to cause dramatic stock price fluctuations and increase investment risk.The quantification of investment sentiment indicators and the persistent analysis of their impact has been a complex and significant area of research.In this paper,a structured multi-head attention stock index prediction method based adaptive public opinion sentiment vector is proposed.The proposedmethod utilizes an innovative approach to transform numerous investor comments on social platforms over time into public opinion sentiment vectors expressing complex sentiments.It then analyzes the continuous impact of these vectors on the market through the use of aggregating techniques and public opinion data via a structured multi-head attention mechanism.The experimental results demonstrate that the public opinion sentiment vector can provide more comprehensive feedback on market sentiment than traditional sentiment polarity analysis.Furthermore,the multi-head attention mechanism is shown to improve prediction accuracy through attention convergence on each type of input information separately.Themean absolute percentage error(MAPE)of the proposedmethod is 0.463%,a reduction of 0.294% compared to the benchmark attention algorithm.Additionally,the market backtesting results indicate that the return was 24.560%,an improvement of 8.202% compared to the benchmark algorithm.These results suggest that themarket trading strategy based on thismethod has the potential to improve trading profits. 展开更多
关键词 Public opinion sentiment structured multi-head attention stock index prediction deep learning
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Developing and validating a predictive model of delivering large-forgestational-age infants among women with gestational diabetes mellitus
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作者 Yi-Tian Zhu Lan-Lan Xiang +3 位作者 Ya-Jun Chen Tian-Ying Zhong Jun-Jun Wang Yu Zeng 《World Journal of Diabetes》 SCIE 2024年第6期1242-1253,共12页
BACKGROUND The birth of large-for-gestational-age(LGA)infants is associated with many shortterm adverse pregnancy outcomes.It has been observed that the proportion of LGA infants born to pregnant women with gestationa... BACKGROUND The birth of large-for-gestational-age(LGA)infants is associated with many shortterm adverse pregnancy outcomes.It has been observed that the proportion of LGA infants born to pregnant women with gestational diabetes mellitus(GDM)is significantly higher than that born to healthy pregnant women.However,traditional methods for the diagnosis of LGA have limitations.Therefore,this study aims to establish a predictive model that can effectively identify women with GDM who are at risk of delivering LGA infants.AIM To develop and validate a nomogram prediction model of delivering LGA infants among pregnant women with GDM,and provide strategies for the effective prevention and timely intervention of LGA.METHODS The multivariable prediction model was developed by carrying out the following steps.First,the variables that were associated with LGA risk in pregnant women with GDM were screened by univariate analyses,for which the P value was<0.10.Subsequently,Least Absolute Shrinkage and Selection Operator regression was fit using ten cross-validations,and the optimal combination factors were se-lected by choosing lambda 1se as the criterion.The final predictors were deter-mined by multiple backward stepwise logistic regression analysis,in which only the independent variables were associated with LGA risk,with a P value<0.05.Finally,a risk prediction model was established and subsequently evaluated by using area under the receiver operating characteristic curve,calibration curve and decision curve analyses.RESULTS After using a multistep screening method,we establish a predictive model.Several risk factors for delivering an LGA infant were identified(P<0.01),including weight gain during pregnancy,parity,triglyceride-glucose index,free tetraiodothyronine level,abdominal circumference,alanine transaminase-aspartate aminotransferase ratio and weight at 24 gestational weeks.The nomogram’s prediction ability was supported by the area under the curve(0.703,0.709,and 0.699 for the training cohort,validation cohort,and test cohort,respectively).The calibration curves of the three cohorts displayed good agreement.The decision curve showed that the use of the 10%-60%threshold for identifying pregnant women with GDM who are at risk of delivering an LGA infant would result in a positive net benefit.CONCLUSION Our nomogram incorporated easily accessible risk factors,facilitating individualized prediction of pregnant women with GDM who are likely to deliver an LGA infant. 展开更多
关键词 Large-for-gestational-age Gestational diabetes mellitus predictive model NOMOGRAM Triglyceride-glucose index
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基于心肺交互作用的PI及PVI联合心率对无痛胃肠镜中低血压的预测价值
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作者 付紫辉 蒋明 +5 位作者 张晓坤 史长喜 肖江强 张以洋 吕英 付群 《广东医学》 2025年第2期272-277,共6页
目的探讨基于心肺交互作用的无创监测指标脉搏血氧灌注指数(PI)及脉搏灌注变异指数(PVI)联合心率对无痛胃肠镜中预测低血压的准确性。方法收集行无痛胃肠镜检查患者108例,根据术中是否发生低血压情况分为低血压组和非低血压组。所有行... 目的探讨基于心肺交互作用的无创监测指标脉搏血氧灌注指数(PI)及脉搏灌注变异指数(PVI)联合心率对无痛胃肠镜中预测低血压的准确性。方法收集行无痛胃肠镜检查患者108例,根据术中是否发生低血压情况分为低血压组和非低血压组。所有行无痛胃肠镜检查患者均进行SpO_(2)、HR、MAP、PI、PVI和心电图监测。观察计算给药前后HR、PI和PVI的变化情况(△HR、△PI、△PVI),并用ROC评估给药前后及术中HR、PI、PVI、△HR、△PI和△PVI联合HR对低血压的预测作用。结果与未发生低血压患者相比,发生低血压患者的△HR+△PI+△PVI联合预测对预测是否低血压的AUC面积为0.803(0.714~0.893)(P<0.001),特异度为0.781,敏感度为0.816,约登指数为0.597。“△HR+△PI”联合预测对预测是否低血压的AUC面积为0.763(0.663~0.863)(P<0.001),特异度为0.687,敏感度为0.789,约登指数为0.476。“△HR+△PVI”联合预测对预测是否低血压的AUC面积为0.717(0.620~0.814)(P<0.001),特异度为0.937,敏感度为0.526,约登指数为0.463。结论HR联合PI、PVI中的任意一个或同时联合PI、PVI作为一个共同监测指标,可以用于预测无痛胃肠镜中低血压的发生,从而降低低血压的发生率。 展开更多
关键词 心肺交互作用 无创监测 脉搏灌注指数 脉搏灌注变异指数 无痛胃肠镜 预测低血压
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基于预测PI的电极面密度控制系统
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作者 唐为庆 任正云 《化工自动化及仪表》 2025年第1期76-82,143,共8页
为解决锂离子电池极片面密度在复杂工业环境下变参数、大干扰、超大时滞的控制难题,设计基于预测PI的面密度控制系统。首先基于电极涂覆工作原理建立其数学模型并设计控制方案,然后在传统粒子群算法的基础上引入交叉变异因子实现预测PI... 为解决锂离子电池极片面密度在复杂工业环境下变参数、大干扰、超大时滞的控制难题,设计基于预测PI的面密度控制系统。首先基于电极涂覆工作原理建立其数学模型并设计控制方案,然后在传统粒子群算法的基础上引入交叉变异因子实现预测PI算法的参数整定。实际应用表明:该控制系统能够实现横向(TD)面密度和纵向(MD)面密度双闭环控制,面密度变异系数CV由0.192%降至0.115%,面密度过程能力指数CPK由1.212提升至2.324,锂离子电池极片面密度的一致性和稳定性得到了极大改善。 展开更多
关键词 预测pi 遗传粒子群算法 锂离子电池 面密度 不确定系统
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Prognostic roles nutritional index in patients with resectable and advanced biliary tract cancers
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作者 Di Zeng Ning-Yuan Wen +2 位作者 Yao-Qun Wang Nan-Sheng Cheng Bei Li 《World Journal of Gastroenterology》 2025年第6期76-88,共13页
BACKGROUND Biliary tract cancer(BTC)is a rare,aggressive malignancy with increasing inci-dence and poor prognosis.Identifying preoperative prognostic factors is crucial for effective risk-benefit assessments and patie... BACKGROUND Biliary tract cancer(BTC)is a rare,aggressive malignancy with increasing inci-dence and poor prognosis.Identifying preoperative prognostic factors is crucial for effective risk-benefit assessments and patient stratification.The prognostic nutritional index(PNI),which reflects immune-inflammatory and nutritional status,has shown prognostic value in various cancers,but its significance in BTC remains unclear.AIM To assess the prognostic value of the preoperative PNI in BTC patients,with a focus on overall survival(OS)and disease-free survival(DFS).METHODS Comprehensive searches were conducted in the PubMed,EMBASE,and Web of Science databases from inception to April 2024.The primary outcomes of interest focused on the associations between the preoperative PNI and the prognosis of BTC patients,specifically OS and disease-free survival(DFS).Statistical analyses were conducted via STATA 17.0 software.RESULTS Seventeen studies encompassing 4645 patients met the inclusion criteria.Meta-analysis revealed that a low PNI was significantly associated with poorer OS[hazard ratio(HR)1.91,95%CI:1.59-2.29;P<0.001]and DFS(HR 1.93,95%CI:1.39-2.67;P<0.001).Subgroup analyses revealed consistent results across BTC subtypes(cholangiocarcinoma and gallbladder cancer)and stages(resectable and advanced).Sensitivity analyses confirmed the robustness of these findings,and no significant publication bias was detected.CONCLUSION This study demonstrated that a low preoperative PNI predicts poor OS and DFS in BTC patients,highlighting its potential as a valuable prognostic tool.Further prospective studies are needed to validate these findings and enhance BTC patient management. 展开更多
关键词 Biliary tract cancer Prognostic nutritional index predictive marker META-ANALYSIS Survival outcomes
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前列腺健康指数联合PI-RADS评分在血清前列腺特异性抗原4~10μg/L前列腺癌患者中的诊断价值
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作者 陈原杰 余天一 李望 《徐州医科大学学报》 2025年第2期146-150,共5页
目的评价血清前列腺特异性抗原(PSA)位于灰区时(4~10μg/L)前列腺健康指数(PHI)、前列腺影像报告和数据系统(PI-RADS)评分诊断前列腺癌的价值,并建立两者联合诊断前列腺癌的预测模型。方法收集2022年11月—2023年12月在徐州医科大学附... 目的评价血清前列腺特异性抗原(PSA)位于灰区时(4~10μg/L)前列腺健康指数(PHI)、前列腺影像报告和数据系统(PI-RADS)评分诊断前列腺癌的价值,并建立两者联合诊断前列腺癌的预测模型。方法收集2022年11月—2023年12月在徐州医科大学附属医院泌尿外科行经会阴前列腺穿刺活检的131例患者(血清PSA 4~10μg/L)的临床资料,根据病理结果分为前列腺癌组(35例)和良性前列腺增生组(96例)。应用二元logistic回归分析评估各变量对前列腺癌的预测价值,建立PHI联合PI-RADS诊断前列腺癌的预测模型Logit(P)。建立各独立变量和预测模型Logit(P)的受试者操作特征(ROC)曲线,比较各因素的曲线下面积,选取各因素和预测模型Logit(P)的最佳截断值,评估其诊断效能。结果2组患者的年龄、总前列腺特异性抗原(tPSA)、游离前列腺特异性抗原比值(%fPSA)、前列腺体积差异无统计学意义(P>0.05),PHI、前列腺特异性抗原同源异构体2(p2PSA)、前列腺健康指数密度(PHID)的差异有统计学意义(P<0.05)。tPSA、%fPSA、p2PSA、PHI、PHID诊断前列腺癌的曲线下面积分别为0.565、0.634、0.771、0.812、0.802。PHI与PI-RADS评分联合的预测模型为:Logit(P)=1.117×PI-RADS评分+0.086×PHI-7.886,预测模型Logit(P)的ROC曲线下面积为0.848,显著高于各单一指标,差异具有统计学意义(P<0.05)。结论PHI在血清PSA 4~10μg/L的前列腺癌患者中诊断效能优于传统的前列腺肿瘤标志物,联合PI-RADS评分建立的联合预测模型的诊断效能高于单一指标,可有效降低前列腺癌的漏诊率,减少不必要的前列腺穿刺。 展开更多
关键词 前列腺健康指数 前列腺癌 pi-RADS评分 前列腺特异性抗原同源异构体2 前列腺特异性抗原 受试者操作特征曲线
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基于预测PI的热泵干燥温湿度解耦控制研究
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作者 赵海波 张静峰 +1 位作者 吴坤 乔玲敏 《控制工程》 CSCD 北大核心 2024年第12期2149-2158,共10页
现有的热泵干燥多侧重于温度控制,不能克服温湿度的耦合作用实现温度与湿度的同时控制,因而提出一种基于预测PI的热泵干燥温湿度解耦控制方法。首先,基于热泵干燥实验数据进行干燥温湿度控制对象的辨识,得到控制对象模型;然后,采用预测... 现有的热泵干燥多侧重于温度控制,不能克服温湿度的耦合作用实现温度与湿度的同时控制,因而提出一种基于预测PI的热泵干燥温湿度解耦控制方法。首先,基于热泵干燥实验数据进行干燥温湿度控制对象的辨识,得到控制对象模型;然后,采用预测比例-积分(proportional integral,PI)算法和动态解耦实现热泵干燥温湿度控制;最后,利用Simulink仿真工具对比分析了PI、比例-积分-微分(proportional integral derivative,PID)、史密斯预估器(Smith predictor)和预测PI(predictive proportional integral)的控制性能、抗干扰能力和解耦效果。结果表明,预测PI控制具有超调量小、振荡小、鲁棒性良好和抗干扰能力强的特点,适合于大惯性、大滞后热泵干燥过程的温湿度多参数控制。 展开更多
关键词 预测pi 热泵干燥 解耦控制
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基于改进灰色预测单神经元PI的全超导托卡马克核聚变发电装置快控电源电流控制
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作者 黄海宏 陈昭 王海欣 《电工技术学报》 EI CSCD 北大核心 2024年第6期1886-1897,共12页
全超导托卡马克核聚变发电装置(EAST)快控电源负载电感的电流受多种不确定环境因素的影响而难以预测,灰色预测无需精确对象模型,只需少量已知信息即可实现输出电流短期预测,已在EAST快控电源中有了一定研究应用。为解决灰色预测在EAST... 全超导托卡马克核聚变发电装置(EAST)快控电源负载电感的电流受多种不确定环境因素的影响而难以预测,灰色预测无需精确对象模型,只需少量已知信息即可实现输出电流短期预测,已在EAST快控电源中有了一定研究应用。为解决灰色预测在EAST快控电源中对突变信号边沿预测精度低和预测延时时间长的问题,提出一种改进灰色预测算法实现输出电流预测。在一个开关周期内对输出电流进行等时长间隔采样4次作为原始序列,将滚动式采样预测改为逐周期采样预测,在实现灰色预测的过程中不必依赖过去几个周期的历史采样信息,只需本周期的4个原始采样值即可实现输出电流的预测。根据预测电流与参考电流误差自适应调整单神经元比例-积分(PI)控制的输出增益,实现输出电流的快速准确控制。仿真和实验结果表明,在EAST快控电源电流预测过程中所提出的改进灰色预测,对比传统灰色预测具有更高的预测精度和更小的预测延时,改进灰色预测变增益单神经元PI控制能够在减小电流超调的同时加快输出电流响应速度。 展开更多
关键词 EAST快控电源 改进灰色预测 逐周期采样预测 变增益单神经元pi
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Peterson图和图D_(m,n)的边PI指数
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作者 张丽 张辉 红霞 《宁夏师范学院学报》 2024年第4期5-15,共11页
利用分析法和分类讨论法,给出Peterson图和D_(m,n)图的边PI指数计算公式,丰富了图的PI指数理论.
关键词 pi指数 Peterson图 图Dm N
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DAB储能变换器双闭环模型预测控制与PI补偿控制策略研究
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作者 陈桂涛 宋晨飞 +2 位作者 刘飞飞 黄伯雄 孙向东 《太阳能学报》 EI CAS CSCD 北大核心 2024年第8期1-9,共9页
针对直流微电网中分布式电源输入输出功率不稳定造成的直流母线电压波动问题,鉴于双有源桥(DAB)储能变换器具有能量双向流动的特点,提出一种基于内模原理的双闭环模型预测控制策略。在分析DAB变换器扩展移相调制原理与特性基础上,重点... 针对直流微电网中分布式电源输入输出功率不稳定造成的直流母线电压波动问题,鉴于双有源桥(DAB)储能变换器具有能量双向流动的特点,提出一种基于内模原理的双闭环模型预测控制策略。在分析DAB变换器扩展移相调制原理与特性基础上,重点研究电压外环和电流内环的模型预测控制策略。针对模型预测控制性能依赖电路参数准确度问题,分别从电路主要参数失配对功率传输和直流母线稳压的影响两个角度出发,深入分析模型参数敏感度。最终设置直流母线电压稳态误差灵敏度区,在误差灵敏度区外仅采用双闭环模型预测控制以保证系统的动态响应性能,在误差灵敏度区内采用双闭环模型预测控制和PI补偿控制以消除系统稳态误差。搭建实验平台进行实验验证,结果表明:在系统受到扰动时,DAB储能变换器可实现快速地充放电对系统进行补偿,混合控制策略可快速保持母线电压的稳定,实现系统功率均衡,增强系统抗扰能力。 展开更多
关键词 微电网 变换器 直流母线电压波动 双有源桥 扩展移相 双闭环模型预测控制 pi补偿控制
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Multivariable PI Type Generalized Predictive Control 被引量:4
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作者 Chen, Zengqiang Zhao, Tianhang Yuan, Zhuzhi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1998年第2期8-13,共6页
This paper presents a multivariable generalized predictive controller with proportion and integration structure by modifying the quadratic criterion of the usual MGPC. The control performance has been improved greatl... This paper presents a multivariable generalized predictive controller with proportion and integration structure by modifying the quadratic criterion of the usual MGPC. The control performance has been improved greatly. The effectiveness of the controller is demonstrated by the simulation result. 展开更多
关键词 predictive control Self-tuning control Multivariable control pi control
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Composition control and temperature inferential control of dividing wall column based on model predictive control and PI strategies 被引量:2
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作者 Jianxin Wang Na Yu +2 位作者 Mengqi Chen Lin Cong Lanyi Sun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期1087-1101,共15页
The dividing wall column (DWC) is considered as a major breakthrough in distillation technology and has good prospect of industrialization. Model predictive control (MPC) is an advanced control strategy that has a... The dividing wall column (DWC) is considered as a major breakthrough in distillation technology and has good prospect of industrialization. Model predictive control (MPC) is an advanced control strategy that has acquired extensive applications in various industries. In this study, MPC is applied to the process for separating ethanol, n-propanol, and n-butanol ternary mixture in a fully thermally coupled DWC. Both composition control and tem- perature inferent/al control are considered. The multiobjective genetic algor/thm function "gamult/obj" in Matlab is used for the weight tuning of MPC. Comparisons are made between the control performances of MPC and PI strategies. Simulation results show that although both MPC and PI schemes can stabilize the DWC in case of feed disturbances, MPC generally behaves better than the PI strategy for both composition control and tempera- ture inferential control, resulting in a more stable and superior performance with lower values of integral of squared error (ISE). 展开更多
关键词 Dividing wall column Composition control Temperature inferential control pi strategy Model predictive control Genetic algorithm
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Delay Margin for Predictive PI Control System 被引量:1
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作者 ZHUHong-Dong SHAOHui-He 《自动化学报》 EI CSCD 北大核心 2005年第4期530-536,共7页
The variation of plant dead-time deeply a?ects the stability of the predictive PI controlsystem. It is important for designing and applying the PPI controller to calculate the delay margin.A criterion of stability for... The variation of plant dead-time deeply a?ects the stability of the predictive PI controlsystem. It is important for designing and applying the PPI controller to calculate the delay margin.A criterion of stability for the PPI system and the quantitive relationship among the delay margin,the time constant of the closed-loop system, and the dead-time of the model are given. A graphicalgorithm to compute the delay margin is also developed. The phenomenon that there exist morethan one stability delay zones is discussed. The algorithm is shown to be precise by some simulations. 展开更多
关键词 植物 死亡时间 预控系统 稳定性分析
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Early peripheral perfusion index predicts 28-day outcome in patients with septic shock 被引量:2
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作者 Cheng Chi Hao Gong +2 位作者 Kai Yang Peng Peng Xiaoxia Zhang 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第5期372-378,共7页
BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic shock.METHODS:This prospective cohort study,conducted at the emergency intensive care unit of Peking Univers... BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic shock.METHODS:This prospective cohort study,conducted at the emergency intensive care unit of Peking University People's Hospital,recruited 200 patients with septic shock between January 2023 and August 2023.These patients were divided into survival(n=84)and death(n=116)groups based on 28-day outcomes.Clinical evaluations included laboratory tests and clinical scores,with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 12 h after admission.Risk factors associated with mortality were analyzed using univariate and multivariate Cox regression analyses.Receiver operator characteristic(ROC)curve was used to assess predictive performance.Mortality rates were compared,and Kaplan-Meier survival plots were created.RESULTS:Compared to the survival group,patients in the death group were older and had more severe liver damage and coagulation dysfunction,necessitating higher norepinephrine doses and increased fl uid replacement.Higher lactate levels and lower PPI levels at 0 h,6 h,and 12 h were observed in the death group.Multivariate Cox regression identifi ed prolonged prothrombin time(PT),decreased 6-h PPI and 12-h PPI as independent risk factors for death.The area under the curves for 6-h PPI and 12-h PPI were 0.802(95%CI 0.742-0.863,P<0.001)and 0.945(95%CI 0.915-0.974,P<0.001),respectively,which were superior to Glasgow Coma Scale(GCS),Sequential Organ Failure Assessment(SOFA)scores(0.864 and 0.928).Cumulative mortality in the low PPI groups at 6 h and 12 h was signifi cantly higher than in the high PPI groups(6-h PPI:77.52%vs.22.54%;12-h PPI:92.04%vs.13.79%,P<0.001).CONCLUSION:PPI may have value in predicting 28-day mortality in patients with septic shock. 展开更多
关键词 Peripheral perfusion index Septic shock PROGNOSIS predictive value
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Predictive plots for conical pick performance using mechanical and elastoplastic properties of rocks
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作者 Serdar Yasar 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2020年第5期1027-1035,共9页
Conical picks are by far the most widely used drag type cutting tools employed on partial face rock excavation machines.The cutting force and specific energy are two important design parameters for the conical pick pe... Conical picks are by far the most widely used drag type cutting tools employed on partial face rock excavation machines.The cutting force and specific energy are two important design parameters for the conical pick performance,and the rock cutting testing is considered as the promising tool for determining these parameters.In the absence of an instrumented cutting rig,researchers generally rely on empirical predictive plots.For this,this paper suggests predictive plots for estimating the cutting force and specific energy,in consideration of the cutting depth to define the cuttability with conical picks.In this context,rock cutting tests were carried out on six volcanic rock samples with varying cutting depths using the unrelieved and relieved cutting modes.The cutting force and specific energy were correlated with the uniaxial compressive strength,Brazilian tensile strength,elasticity modulus,and plasticity index.Predictive plots were proposed for different cutting depths in the unrelieved and relieved cutting modes and exponential relationships were obtained among the cuttability parameters,and mechanical and elastoplastic properties of rocks. 展开更多
关键词 Performance prediction Rock cutting tests Specific energy Cutting force Plasticity index
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Predictive value of extravascular lung water indexed to predicted body weight
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作者 Fu-Tsai Chung Shu-Min Lin +6 位作者 Horng-Chyuan Lin Chih-Teng Yu Meng-Heng Hsieh Yueh-Fu Fang Chien-Yin Liu Chih-Hsi Kuo Tsai-Yu Wang 《World Journal of Anesthesiology》 2014年第1期124-128,共5页
AIM: To investigate extravascular lung water indexed to predicted body weight(EVLWIp) and actual body weight(EVLWIa) on outcome of patients with severe sepsis.METHODS: Transpulmonary thermodilution was prospectively u... AIM: To investigate extravascular lung water indexed to predicted body weight(EVLWIp) and actual body weight(EVLWIa) on outcome of patients with severe sepsis.METHODS: Transpulmonary thermodilution was prospectively used to measure cardiovascular hemodynamics, EVLWIp and EVLWIa via an arterial catheter placed in each patient within 48 h of meeting the criteria for severe sepsis from a medical intensive care unit(ICU) at a university affiliated hospital. Survival was the single dependent variable. In order to examine and compare the predictive power of EVLWIp, EVLWIa and other clinically significant factors in predicting the inhospital survival status of severe sepsis patients in the medical ICU, a receiver operating characteristic(ROC) curve method to analyze the significant variables and the area under the ROC curve(AUC) of the variables, P value and 95%CI were calculated.RESULTS: In total, 33 patients were studied. In the ROC curve method analyses, EVLWIp(the AUC: 0.849; P = 0.001, 95%CI: 0.72-0.98) was as predictive for inhospital survival rate as variables with EVLWIa(AUC, 0.829; P = 0.001, 95%CI: 0.68-0.98). The proportion of patients surviving with a low EVLW(EVLWI < 10 m L/kg) was better than that of patients with a higher EVLW, whether indexed by actual(HR = 0.2; P = 0.0002, 95%CI: 0.06-0.42) or predicted body weight(HR = 0.13; P < 0.0001, 95%CI: 0.05-0.35) during their hospital stay with the Kaplan-Meier method(76% vs 12.5%, respectively).CONCLUSION: This investigation proposed that EVLWIp is as good a predictor as EVLWIa to predict inhospital survival rate among severe sepsis patients in the medical ICU. 展开更多
关键词 Extravascular LUNG water index Predicted BODY WEIGHT Actual BODY WEIGHT IN-HOSpiTAL survival SEVERE SEPSIS
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Identification of Empirical Models for the Prediction of the Plasticity Index:Case of the KhôDepression in South Benin
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作者 Koffi Judicaël AGBELELE Yvette Sèdjro TANKPINOU KIKI +1 位作者 Abalo P’KLA Gbênihon Céleste-Amour KENOUKON 《材料科学与工程(中英文A版)》 2022年第2期55-66,共12页
The plasticity index is an essential design parameter used as a standard input in fine-grained soil investigation programs.It is used to estimate the plasticity and physical properties of soils,and indirectly their st... The plasticity index is an essential design parameter used as a standard input in fine-grained soil investigation programs.It is used to estimate the plasticity and physical properties of soils,and indirectly their strength properties.This index is determined from the Atterberg limit tests,starting from the limits of liquidity and plasticity.However,the realization of the test considered as basic and simple,is not so much.The effects of the operator,the calibration of the apparatus and the environmental aspects during the tests affect the reliability and accuracy of the results.In this paper,the objective is to overcome these difficulties by evaluating the plasticity index of clay and loam soils by considering only the values of the liquid limit.Soil samples were collected from 0 to 5 m depth in the localities of the Khôdepression in Benin.On these samples,Atterberg limit tests were performed in the laboratory.Using MATLAB’s Curve Fitting Toolbox,linear,exponential and power prediction models were analyzed.The results showed that there is indeed a good correlation between the plasticity index and the liquid limit of the soils.For the linear model,it was observed R2 equal to 0.9891.For the exponential model,R2 is 0.98871 and for the power model 0.9802.A study of the residual plot validated the models found,as well as comparisons with well-known literature sources.Through the equations obtained,it is now possible to study the plasticity of soils in the Khôdepression only from the liquid limit,without determining the plasticity limit. 展开更多
关键词 Plasticity index liquidity limit PREDICTION regression model Lama depression Khôdepression
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广义齿轮图的PI指数
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作者 弓文慧 邵燕灵 《中北大学学报(自然科学版)》 CAS 2024年第3期296-300,共5页
设G是简单连通图,e=uv是G中连接点u和点v的一条边,图G的PI指数定义为PI(G)=[neu(e|G)+nev(e|G)]。一个顶点到一条边的距离就是该点与该边的两个端点之间的最小距离。广义齿轮图是通过在圆锥图的圈上的每对相邻顶点之间添加一个顶点而得... 设G是简单连通图,e=uv是G中连接点u和点v的一条边,图G的PI指数定义为PI(G)=[neu(e|G)+nev(e|G)]。一个顶点到一条边的距离就是该点与该边的两个端点之间的最小距离。广义齿轮图是通过在圆锥图的圈上的每对相邻顶点之间添加一个顶点而得到的图,其具有优美的对称性。记广义齿轮图C*的PI指数为PI(C*),本文根据广义齿轮图的性质,得到了一种计算与一条边的两个端点距离相等的边的方法,并将其边进行分类,利用此方法找到对PI(C*)没有贡献的边,从而计算出广义齿轮图的PI指数,为研究一些特殊图的PI指数问题提供了线索。 展开更多
关键词 pi指数 广义齿轮图 偶圈 对称性
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齿轮图及其一致膨胀图的PI指数
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作者 弓文慧 邵燕灵 《贵州大学学报(自然科学版)》 2024年第1期27-30,42,共5页
齿轮图就是在轮图的轮圈上每相邻两点之间均添加一个顶点后得到的图,由于齿轮图有很好的对称性,所以将其边进行分类,计算出齿轮图的PI指数。齿轮图的一致膨胀图就是将它的每个顶点都替换成阶相等的完全图,通过与齿轮图类比,计算其一致... 齿轮图就是在轮图的轮圈上每相邻两点之间均添加一个顶点后得到的图,由于齿轮图有很好的对称性,所以将其边进行分类,计算出齿轮图的PI指数。齿轮图的一致膨胀图就是将它的每个顶点都替换成阶相等的完全图,通过与齿轮图类比,计算其一致膨胀图的PI指数,为研究一些特殊图形的PI指数问题提供了线索。 展开更多
关键词 pi指数 齿轮图 一致膨胀图 图对称性 类比
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