A switching variability index (SVl) constant false alarm rate (CFAR) detector is proposed for improving the detection performance of VI-CFAR detectors in multiple targets backgrounds. When the presence of non-homo...A switching variability index (SVl) constant false alarm rate (CFAR) detector is proposed for improving the detection performance of VI-CFAR detectors in multiple targets backgrounds. When the presence of non-homogeneity in CFAR reference windows is indicated by a VI-CFAR detector, a switching- CFAR detector is introduced to optimize the performance of the VI-CFAR detector in homogeneous, multiple targets and clutter edge backgrounds. The structure and parameters selection method of the SVI-CFAR detector is presented. Comparisons with classic CFAR detectors and recently proposed detectors are also given. Theoretical analysis and simulation results show that SVICFAR detector maintains the good performance of the VI-CFAR detector in homogeneous and clutter edge backgrounds, while greatly improving the capacity of anti-multi targets.展开更多
Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, res...Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, resuscitation should achieve a central venous pressure (CVP) of 8-12 mmHg within the first 6 h. However, it is still uncertain about the sensitivity and specificity of CVP in reflecting the cardiac preload. Ultrasonography is a simple, rapid, non-invasive, and repeatable method for the measurement of sensitivity and specificity of CVP and has thus gradually attracted the increasing attention of physicians. It was reported that ultrasonography can show the inferior vena cava diameter, respiratory variability index, and blood volume in patients with sepsis or heart failure.展开更多
The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and econ...The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and economics. In this work, we obtained the general formula of mean difference, which is not yet reported in literature, for the aforementioned distribution model and also for particular truncated cases.展开更多
The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span sty...The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in particular, of an important distribution model known as Tukey lambda, which is generally used to choose a model to fit data.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">We have obtained compact formulas, which are not yet reported in literature, of mean deviation and mean difference related to the said distribution model.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">These results made it possible to analyze the relationships among variability indexes, namely standard deviation, mean deviation and mean difference, regarding Tukey lambda model.</span></span></span>展开更多
In the case of Z+^d(d ≥ 2)-the positive d-dimensional lattice points with partial ordering ≤, {Xk,k∈ Z+^d} i.i.d, random variables with mean 0, Sn =∑k≤nXk and Vn^2 = ∑j≤nXj^2, the precise asymptotics for ∑...In the case of Z+^d(d ≥ 2)-the positive d-dimensional lattice points with partial ordering ≤, {Xk,k∈ Z+^d} i.i.d, random variables with mean 0, Sn =∑k≤nXk and Vn^2 = ∑j≤nXj^2, the precise asymptotics for ∑n1/|n|(log|n|dP(|Sn/Vn|≥ε√log log|n|) and ∑n(logn|)b/|n|(log|n|)^d-1P(|Sn/Vn|≥ε√log n),as ε↓0,is established.展开更多
Background: Non-invasive goal directed fluid therapy during deceased donor renal transplant (CRT) may reduce the incidence of delayed graft function. Plethysmograph Variability Index (PVI) has been shown to predict fl...Background: Non-invasive goal directed fluid therapy during deceased donor renal transplant (CRT) may reduce the incidence of delayed graft function. Plethysmograph Variability Index (PVI) has been shown to predict fluid responsiveness during surgery. This pilot study evaluated the feasibility of goal directed fluid administration protocol based upon PVI studying the incidence of delayed graft function (DGF) in renal transplant recipients. Methods: Twenty patients underwent primary CRT. The Control group received intravenous fluid (IVF) at a calculated constant rate. The Treatment group received a baseline IVF infusion throughout the surgery. PVI values greater than 13% were treated with 250 ml boluses of IVF. Primary end point was DGF;total IVF administration and urinary biomarker NGAL levels were secondary endpoints. Results: Treatment group at every time point received significantly less IVF. There was no significant difference in incidence of DGF between the groups. 2 patients in the Control group and 6 in the Treatment group developed DGF. NGAL was not associated with the group assignment or total IVF given (p < 0.2). Conclusions: The effectiveness of goal directed fluid therapy with non-invasive dynamic parameters has not been validated in renal transplant surgery and larger prospective studies are needed to determine its utility in renal transplantation.展开更多
The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables, i.e., subjective random and fuzzy variables. In o...The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables, i.e., subjective random and fuzzy variables. In order to simultaneously satisfy the duality of randomness and subadditivity of fuzziness in the reliability problem, a new quantification method for the reliability of structures is presented based on uncertainty theory, and an uncertainty-theory-based perspective of classical Cornell reliability index is explored. In this paper, by introducing the uncertainty theory, we adopt the uncertain measure to quantify the reliability of structures for the subjective probability or fuzzy variables, instead of probabilistic and possibilistic measures. We utilize uncertain variables to uniformly represent the subjective random and fuzzy parameters, based on which we derive solutions to analyze the uncertainty reliability of structures with uncertainty distributions. Moreover, we propose the Cornell uncertainty reliability index based on the uncertain expected value and variance.Experimental results on three numerical applications demonstrate the validity of the proposed method.展开更多
基金supported by the National Natural Science Foundation of China(61102158)the China Postdoctoral Science Foundation(2011M500667)
文摘A switching variability index (SVl) constant false alarm rate (CFAR) detector is proposed for improving the detection performance of VI-CFAR detectors in multiple targets backgrounds. When the presence of non-homogeneity in CFAR reference windows is indicated by a VI-CFAR detector, a switching- CFAR detector is introduced to optimize the performance of the VI-CFAR detector in homogeneous, multiple targets and clutter edge backgrounds. The structure and parameters selection method of the SVI-CFAR detector is presented. Comparisons with classic CFAR detectors and recently proposed detectors are also given. Theoretical analysis and simulation results show that SVICFAR detector maintains the good performance of the VI-CFAR detector in homogeneous and clutter edge backgrounds, while greatly improving the capacity of anti-multi targets.
文摘Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, resuscitation should achieve a central venous pressure (CVP) of 8-12 mmHg within the first 6 h. However, it is still uncertain about the sensitivity and specificity of CVP in reflecting the cardiac preload. Ultrasonography is a simple, rapid, non-invasive, and repeatable method for the measurement of sensitivity and specificity of CVP and has thus gradually attracted the increasing attention of physicians. It was reported that ultrasonography can show the inferior vena cava diameter, respiratory variability index, and blood volume in patients with sepsis or heart failure.
文摘The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and economics. In this work, we obtained the general formula of mean difference, which is not yet reported in literature, for the aforementioned distribution model and also for particular truncated cases.
文摘The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in particular, of an important distribution model known as Tukey lambda, which is generally used to choose a model to fit data.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">We have obtained compact formulas, which are not yet reported in literature, of mean deviation and mean difference related to the said distribution model.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">These results made it possible to analyze the relationships among variability indexes, namely standard deviation, mean deviation and mean difference, regarding Tukey lambda model.</span></span></span>
文摘In the case of Z+^d(d ≥ 2)-the positive d-dimensional lattice points with partial ordering ≤, {Xk,k∈ Z+^d} i.i.d, random variables with mean 0, Sn =∑k≤nXk and Vn^2 = ∑j≤nXj^2, the precise asymptotics for ∑n1/|n|(log|n|dP(|Sn/Vn|≥ε√log log|n|) and ∑n(logn|)b/|n|(log|n|)^d-1P(|Sn/Vn|≥ε√log n),as ε↓0,is established.
文摘Background: Non-invasive goal directed fluid therapy during deceased donor renal transplant (CRT) may reduce the incidence of delayed graft function. Plethysmograph Variability Index (PVI) has been shown to predict fluid responsiveness during surgery. This pilot study evaluated the feasibility of goal directed fluid administration protocol based upon PVI studying the incidence of delayed graft function (DGF) in renal transplant recipients. Methods: Twenty patients underwent primary CRT. The Control group received intravenous fluid (IVF) at a calculated constant rate. The Treatment group received a baseline IVF infusion throughout the surgery. PVI values greater than 13% were treated with 250 ml boluses of IVF. Primary end point was DGF;total IVF administration and urinary biomarker NGAL levels were secondary endpoints. Results: Treatment group at every time point received significantly less IVF. There was no significant difference in incidence of DGF between the groups. 2 patients in the Control group and 6 in the Treatment group developed DGF. NGAL was not associated with the group assignment or total IVF given (p < 0.2). Conclusions: The effectiveness of goal directed fluid therapy with non-invasive dynamic parameters has not been validated in renal transplant surgery and larger prospective studies are needed to determine its utility in renal transplantation.
基金co-supported by the National Natural Science Foundation of China (Nos. 51675026 and 71671009)the National Basic Research Program of China (No. 2013CB733002)
文摘The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables, i.e., subjective random and fuzzy variables. In order to simultaneously satisfy the duality of randomness and subadditivity of fuzziness in the reliability problem, a new quantification method for the reliability of structures is presented based on uncertainty theory, and an uncertainty-theory-based perspective of classical Cornell reliability index is explored. In this paper, by introducing the uncertainty theory, we adopt the uncertain measure to quantify the reliability of structures for the subjective probability or fuzzy variables, instead of probabilistic and possibilistic measures. We utilize uncertain variables to uniformly represent the subjective random and fuzzy parameters, based on which we derive solutions to analyze the uncertainty reliability of structures with uncertainty distributions. Moreover, we propose the Cornell uncertainty reliability index based on the uncertain expected value and variance.Experimental results on three numerical applications demonstrate the validity of the proposed method.