Strengthening soft foundation by vacuum loading from lower position is a new method of accelerating the consolidation of dredger fill. This paper presents the mechanism of soft foundation strengthening by vacuum loadi...Strengthening soft foundation by vacuum loading from lower position is a new method of accelerating the consolidation of dredger fill. This paper presents the mechanism of soft foundation strengthening by vacuum loading from lower position and evaluates the effectiveness of this method under various boundary conditions by means of finite element method (FEM) on the basis of Biot's consolidation theory.展开更多
Concern on alteration of sediment natural flow caused by developments of water resources system, has been addressed in many river basins around the world especially in developing and remote regions where sediment data...Concern on alteration of sediment natural flow caused by developments of water resources system, has been addressed in many river basins around the world especially in developing and remote regions where sediment data are poorly gauged or ungauged. Since suspended sediment load (SSL) is predominant, the objectives of this research are to: 1) simulate monthly average SSL (SSLm) of four catchments using artificial neural network (ANN);2) assess the application of the calibrated ANN (Cal-ANN) models in three ungauged catchment representatives (UCR) before using them to predict SSLm of three actual ungauged catchments (AUC) in the Tonle Sap River Basin;and 3) estimate annual SSL (SSLA) of each AUC for the case of with and without dam-reservoirs. The model performance for total load (SSLT) prediction was also investigated because it is important for dam-reservoir management. For model simulation, ANN yielded very satisfactory results with determination coefficient (R2) ranging from 0.81 to 0.94 in calibration stage and 0.63 to 0.87 in validation stage. The Cal-ANN models also performed well in UCRs with R2 ranging from 0.59 to 0.64. From the result of this study, one can estimate SSLm and SSLT of ungauged catchments with an accuracy of 0.61 in term of R2 and 34.06% in term of absolute percentage bias, respectively. SSLA of the AUCs was found between 159,281 and 723,580 t/year. In combination with Brune’s method, the impact of dam-reservoirs could reduce SSLA between 47% and 68%. This result is key information for sustainable development of such infrastructures.展开更多
目的:探讨下肢深静脉血栓的相关影响因素以及负荷评分对急性肺栓塞诊断价值。方法:回顾性分析超声确诊的下肢静脉血栓患者116例,根据是否存在急性肺栓塞将患者分为:下肢静脉血栓合并急性肺栓塞(venous thrombosis embolism was associat...目的:探讨下肢深静脉血栓的相关影响因素以及负荷评分对急性肺栓塞诊断价值。方法:回顾性分析超声确诊的下肢静脉血栓患者116例,根据是否存在急性肺栓塞将患者分为:下肢静脉血栓合并急性肺栓塞(venous thrombosis embolism was associated with acute pulmonary embolism,VT-APE)组和下肢静脉血栓不合并急性肺栓塞(venous thrombosis embolism was not associated with acute pulmonary embolism,VT-N-APE)组。探讨下肢静脉血栓超声声像学特征及血栓的负荷评分对急性肺栓塞的影响。Logistic多因素分析下肢深静脉血栓的患者中形成急性肺栓塞的相关危险因素。结果:VT-APE组61例,男23例,女38例,VT-APE组下肢股腘静脉血栓8例(13.1%),低回声22例(78.6%),下肢肌间静脉血栓占32例(52.5%),低回声55例(90.1%);股腘静脉合并小腿肌间静脉21例(34.4%),低回声42例(68.8%),下肢深静脉血栓超声声像图负荷评分287分。VT-N-APE组55例,男25例,女30例,下肢股腘深静脉血栓7例(12.6%),低回声16例(100%),下肢肌间静脉血栓45例(81.9%),低回声48例(87.2%)。股腘合并小腿肌间静脉3例(5.5%),低回声50例(90%),下肢深静脉血栓超声声像图负荷评分130分。单因素分析两组在D-Dimer、FDP、下肢深静脉血栓超声声像图负荷评分等差异有统计学意义(P<0.05)。Logistics多因素分析显示高龄、超重肥胖、D-Dimer、FDP、下肢深静脉超声声像图血栓负荷评分(P<0.05)是急性肺栓塞的危险因素。结论:VT-APE组下肢深静脉血栓超声声像图负荷评分高于VT-N-APE组,受累下肢静脉血栓的梗阻长度及静脉受累的数目是急性肺栓塞的危险因素。用下肢深静脉血栓超声声像图负荷评分可以提升急性肺栓塞的诊断价值。展开更多
文摘Strengthening soft foundation by vacuum loading from lower position is a new method of accelerating the consolidation of dredger fill. This paper presents the mechanism of soft foundation strengthening by vacuum loading from lower position and evaluates the effectiveness of this method under various boundary conditions by means of finite element method (FEM) on the basis of Biot's consolidation theory.
文摘Concern on alteration of sediment natural flow caused by developments of water resources system, has been addressed in many river basins around the world especially in developing and remote regions where sediment data are poorly gauged or ungauged. Since suspended sediment load (SSL) is predominant, the objectives of this research are to: 1) simulate monthly average SSL (SSLm) of four catchments using artificial neural network (ANN);2) assess the application of the calibrated ANN (Cal-ANN) models in three ungauged catchment representatives (UCR) before using them to predict SSLm of three actual ungauged catchments (AUC) in the Tonle Sap River Basin;and 3) estimate annual SSL (SSLA) of each AUC for the case of with and without dam-reservoirs. The model performance for total load (SSLT) prediction was also investigated because it is important for dam-reservoir management. For model simulation, ANN yielded very satisfactory results with determination coefficient (R2) ranging from 0.81 to 0.94 in calibration stage and 0.63 to 0.87 in validation stage. The Cal-ANN models also performed well in UCRs with R2 ranging from 0.59 to 0.64. From the result of this study, one can estimate SSLm and SSLT of ungauged catchments with an accuracy of 0.61 in term of R2 and 34.06% in term of absolute percentage bias, respectively. SSLA of the AUCs was found between 159,281 and 723,580 t/year. In combination with Brune’s method, the impact of dam-reservoirs could reduce SSLA between 47% and 68%. This result is key information for sustainable development of such infrastructures.
文摘目的:探讨下肢深静脉血栓的相关影响因素以及负荷评分对急性肺栓塞诊断价值。方法:回顾性分析超声确诊的下肢静脉血栓患者116例,根据是否存在急性肺栓塞将患者分为:下肢静脉血栓合并急性肺栓塞(venous thrombosis embolism was associated with acute pulmonary embolism,VT-APE)组和下肢静脉血栓不合并急性肺栓塞(venous thrombosis embolism was not associated with acute pulmonary embolism,VT-N-APE)组。探讨下肢静脉血栓超声声像学特征及血栓的负荷评分对急性肺栓塞的影响。Logistic多因素分析下肢深静脉血栓的患者中形成急性肺栓塞的相关危险因素。结果:VT-APE组61例,男23例,女38例,VT-APE组下肢股腘静脉血栓8例(13.1%),低回声22例(78.6%),下肢肌间静脉血栓占32例(52.5%),低回声55例(90.1%);股腘静脉合并小腿肌间静脉21例(34.4%),低回声42例(68.8%),下肢深静脉血栓超声声像图负荷评分287分。VT-N-APE组55例,男25例,女30例,下肢股腘深静脉血栓7例(12.6%),低回声16例(100%),下肢肌间静脉血栓45例(81.9%),低回声48例(87.2%)。股腘合并小腿肌间静脉3例(5.5%),低回声50例(90%),下肢深静脉血栓超声声像图负荷评分130分。单因素分析两组在D-Dimer、FDP、下肢深静脉血栓超声声像图负荷评分等差异有统计学意义(P<0.05)。Logistics多因素分析显示高龄、超重肥胖、D-Dimer、FDP、下肢深静脉超声声像图血栓负荷评分(P<0.05)是急性肺栓塞的危险因素。结论:VT-APE组下肢深静脉血栓超声声像图负荷评分高于VT-N-APE组,受累下肢静脉血栓的梗阻长度及静脉受累的数目是急性肺栓塞的危险因素。用下肢深静脉血栓超声声像图负荷评分可以提升急性肺栓塞的诊断价值。
