The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Lynn R Willis - One of the best experts on this subject based on the ideXlab platform.
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effect of Initial Shock wave voltage on Shock wave lithotripsy induced lesion size during step wise voltage ramping
BJUI, 2009Co-Authors: Bret A Connors, Andrew P Evan, Philip M Blomgren, Rajash K Handa, Lynn R WillisAbstract:OBJECTIVE To determine if the starting voltage in a step-wise ramping protocol for extracorporeal Shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS To address this question, one kidney from 19 juvenile pigs (aged 7–8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3–4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS The data suggest that Initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the Initial Shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.
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Effect of Initial Shock wave voltage on Shock wave lithotripsy‐induced lesion size during step‐wise voltage ramping
BJUI, 2008Co-Authors: Bret A Connors, Andrew P Evan, Philip M Blomgren, Rajash K Handa, Lynn R WillisAbstract:OBJECTIVE To determine if the starting voltage in a step-wise ramping protocol for extracorporeal Shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS To address this question, one kidney from 19 juvenile pigs (aged 7–8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3–4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS The data suggest that Initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the Initial Shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.
Osman Yağan - One of the best experts on this subject based on the ideXlab platform.
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Robustness of Interdependent Cyber-Physical Systems Against Cascading Failures
IEEE Transactions on Automatic Control, 2020Co-Authors: Yingrui Zhang, Osman YağanAbstract:Integrated cyber-physical systems, such as the smart-grid, are increasingly becoming the underpinning technology for major industries. A major concern regarding such systems are the seemingly unexpected large scale failures, which are often attributed to a small Initial Shock getting escalated due to intricate dependencies within and across the individual (e.g., cyber and physical) counterparts of the system. In this paper, we develop a novel interdependent system model to capture this phenomenon, also known as cascading failures. Our framework consists of two networks that have inherently different characteristics governing their intradependence: first, a cyber-network where a node is deemed to be functional as long as it belongs to the largest connected (i.e., giant) component; and, second, a physical network where nodes are given an Initial flow and a capacity, and failure of a node results with redistribution of its flow to the remaining nodes, upon which further failures might take place due to overloading (i.e., the flow of a node exceeding its capacity). Furthermore, it is assumed that these two networks are interdependent. For simplicity, we consider a one-to-one interdependence model where every node in the cyber-network is dependent upon and supports a single node in the physical network, and vice versa. We provide a thorough analysis of the dynamics of cascading failures in this interdependent system initiated with a random attack. The system robustness is quantified as the surviving fraction of nodes at the end of cascading failures, and is derived in terms of all network parameters involved (e.g., degree distribution, load/capacity distribution, failure size, etc.). Analytic results are supported through an extensive numerical study. Among other things, these results demonstrate the ability of our model to capture the unexpected nature of large-scale failures, and provide insights on improving system robustness.
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Modeling and Analysis of Cascading Failures in Interdependent Cyber-Physical Systems
2018 IEEE Conference on Decision and Control (CDC), 2018Co-Authors: Yingrui Zhang, Osman YağanAbstract:Integrated cyber-physical systems (CPSs), such as the smart grid, are becoming the underpinning technology for major industries. A major concern regarding such systems are the seemingly unexpected large scale failures, which are often attributed to a small Initial Shock getting escalated due to intricate dependencies within and across the individual counterparts of the system. In this paper, we develop a novel interdependent system model to capture this phenomenon, also known as cascading failures. Our framework consists of two networks that have inherently different characteristics governing their intra-dependency: i) a cyber-network where a node is deemed to be functional as long as it belongs to the largest connected (i.e., giant) component; and ii) a physical network where nodes are given an Initial flow and a capacity, and failure of a node results with redistribution of its flow to the remaining nodes, upon which further failures might take place due to overloading. Furthermore, it is assumed that these two networks are inter-dependent. For simplicity, we consider a one-to-one interdependency model where every node in the cyber-network is dependent upon and supports a single node in the physical network, and vice versa. We provide a thorough analysis of the dynamics of cascading failures in this interdependent system initiated with a random attack. The system robustness is quantified as the surviving fraction of nodes at the end of cascading failures, and is derived in terms of all network parameters involved. Analytic results are supported through an extensive numerical study. Among other things, these results demonstrate the ability of our model to capture the unexpected nature of large-scale failures, and provide insights on improving system robustness.
Feifei Li - One of the best experts on this subject based on the ideXlab platform.
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reduction of Initial Shock in decadal predictions using a new Initialization strategy
Geophysical Research Letters, 2017Co-Authors: Yujun He, Bin Wang, Yongqiang Yu, Ruizhe Li, Cheng Zhang, Shiming Xu, Wenyu Huang, Yong Wang, Feifei LiAbstract:A novel full-field Initialization strategy based on the dimension-reduced projection four-dimensional variational data assimilation (DRP-4DVar) is proposed to alleviate the well-known Initial Shock occurring in the early years of decadal predictions. It generates consistent Initial conditions, which best fit the monthly mean oceanic analysis data along the coupled model trajectory in 1 month windows. Three indices to measure the Initial Shock intensity are also proposed. Results indicate that this method does reduce the Initial Shock in decadal predictions by Flexible Global Ocean-Atmosphere-Land System model, Grid-point version 2 (FGOALS-g2) compared with the three-dimensional variational data assimilation-based nudging full-field Initialization for the same model and is comparable to or even better than the different Initialization strategies for other fifth phase of the Coupled Model Intercomparison Project (CMIP5) models. Better hindcasts of global mean surface air temperature anomalies can be obtained than in other FGOALS-g2 experiments. Due to the good model response to external forcing and the reduction of Initial Shock, higher decadal prediction skill is achieved than in other CMIP5 models.
Bret A Connors - One of the best experts on this subject based on the ideXlab platform.
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effect of Initial Shock wave voltage on Shock wave lithotripsy induced lesion size during step wise voltage ramping
BJUI, 2009Co-Authors: Bret A Connors, Andrew P Evan, Philip M Blomgren, Rajash K Handa, Lynn R WillisAbstract:OBJECTIVE To determine if the starting voltage in a step-wise ramping protocol for extracorporeal Shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS To address this question, one kidney from 19 juvenile pigs (aged 7–8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3–4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS The data suggest that Initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the Initial Shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.
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Effect of Initial Shock wave voltage on Shock wave lithotripsy‐induced lesion size during step‐wise voltage ramping
BJUI, 2008Co-Authors: Bret A Connors, Andrew P Evan, Philip M Blomgren, Rajash K Handa, Lynn R WillisAbstract:OBJECTIVE To determine if the starting voltage in a step-wise ramping protocol for extracorporeal Shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS To address this question, one kidney from 19 juvenile pigs (aged 7–8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3–4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS The data suggest that Initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the Initial Shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.
Bin Wang - One of the best experts on this subject based on the ideXlab platform.
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reduction of Initial Shock in decadal predictions using a new Initialization strategy
Geophysical Research Letters, 2017Co-Authors: Yujun He, Bin Wang, Yongqiang Yu, Ruizhe Li, Cheng Zhang, Shiming Xu, Wenyu Huang, Yong Wang, Feifei LiAbstract:A novel full-field Initialization strategy based on the dimension-reduced projection four-dimensional variational data assimilation (DRP-4DVar) is proposed to alleviate the well-known Initial Shock occurring in the early years of decadal predictions. It generates consistent Initial conditions, which best fit the monthly mean oceanic analysis data along the coupled model trajectory in 1 month windows. Three indices to measure the Initial Shock intensity are also proposed. Results indicate that this method does reduce the Initial Shock in decadal predictions by Flexible Global Ocean-Atmosphere-Land System model, Grid-point version 2 (FGOALS-g2) compared with the three-dimensional variational data assimilation-based nudging full-field Initialization for the same model and is comparable to or even better than the different Initialization strategies for other fifth phase of the Coupled Model Intercomparison Project (CMIP5) models. Better hindcasts of global mean surface air temperature anomalies can be obtained than in other FGOALS-g2 experiments. Due to the good model response to external forcing and the reduction of Initial Shock, higher decadal prediction skill is achieved than in other CMIP5 models.