We consider a statically determinate structural truss problem where all of the physical model parameters are uncertain： not just the material values and applied loads, but also the positions of the nodes are assumed ...We consider a statically determinate structural truss problem where all of the physical model parameters are uncertain： not just the material values and applied loads, but also the positions of the nodes are assumed to be inexact but bounded and are represented by intervals. Such uncertainty may typically arise from imprecision during the process of manufacturing or construction, or round-off errors. In this case the application of the finite element method results in a system of linear equations with numerous interval parameters which cannot be solved conventionally. Applying a suitable variable substitution, an iteration method for the solution of a parametric system of linear equations is firstly employed to obtain initial bounds on the node displacements. Thereafter, an interval tightening （pruning） technique is applied, firstly on the element forces and secondly on the node displacements, in order to obtain tight guaranteed enclosures for the interval solutions for the forces and displacements.展开更多
The cytology of 130 indeterminate nodules （Thy 3） was retrospectively reviewed according to the British Thyroid Association 2014 classification. Nodules were divided into Thy 3a （atypical features） and Thy 3f （fo...The cytology of 130 indeterminate nodules （Thy 3） was retrospectively reviewed according to the British Thyroid Association 2014 classification. Nodules were divided into Thy 3a （atypical features） and Thy 3f （follicular lesion） categories. Histology was available as a reference for 97 nodules. Pre-surgical evaluations comprised biochemical tests, color-Doppler ultrasonogrephy （US）, semi-quantitative elastography-US （USE）, contrast-enhanced US （CEUS）, and mutation analysis from cytological slides. Thyroid malignancy was the final diagnosis for 19% of surgically- treated nodules. No statistically significant difference in the risk of malignancy was found between Thy 3a （26%） and Thy 3f （14%） nodules. Histology of the Thy 3a and Thy 3f nodules showed a higher incidence of Hurtle cell adenomas in Thy 3f （29%） than in Thy 3a （3%） nodules （P=0.01）. The only pre-surgical difference concerned the BRAF V600E mutation, which was positive in some Thy 3a but not in any Thy 3f nodules （P=0.04）. Receiver-operating characteristic （ROC） analysis was used to obtain cut-off values from US （score）, USE （ELX 2/1 strain index）, and CEUS （time-to- peak index and peak index） data. The cut-off values were similar for Thy 3a and Thy 3f nodules. Data showed that malignancy can be suspected if the US score is 〉2, ELX 1/2 strain index 〉1, time-to-peakindex 〉1, and peak index 〈1. In a sub-group of 24 revised nodules （12 Thy 3a and 12 Thy 3f） with histology as a reference, the diagnostic power of cumulative pre-surgical analysis by means of US, USE, and CEUS showed high positive and negative predictive values （83% and 100%, respectively） for the presence of malignancy in Thy 3a and Thy 3f nodules. In conclusion, in our series of revised Thy 3 nodules, malignancy was low and displayed no significant differences between Thy 3a and Thy 3f categories. The use of cut-offs based on histology as a reference could reduce surgery. Our data support the conviction that, in mutation-negative Thy 3a and Thy 3f nodules, observation should be the first choice when not all instrumental results are suspect.展开更多
Over the past decades, complex networks have been prosperous greatly in various fields of sciences and engineering. Much attention has been given to investigate the synchronization of complex networks in recent years....Over the past decades, complex networks have been prosperous greatly in various fields of sciences and engineering. Much attention has been given to investigate the synchronization of complex networks in recent years. However, few work has done for the networks with uncertain parameters and unknown topology. In this paper, to further reveal the dynamical mechanism in complex networks with time delays, an uncertain general complex dynamical network with delayed nodes is studied. By constructing a drive network and a suitable slave network, several novel criteria for the networks consisting of the identical nodes and different nodes have been obtained based on the adaptive feedback method. Particularly, the hypotheses and the proposed adaptive laws for network synchronization are simple and can be readily applied in practical applications. Finally, numerical simulations are provided to illustrate the effectiveness of the proposed synchronization criteria.展开更多
文摘We consider a statically determinate structural truss problem where all of the physical model parameters are uncertain： not just the material values and applied loads, but also the positions of the nodes are assumed to be inexact but bounded and are represented by intervals. Such uncertainty may typically arise from imprecision during the process of manufacturing or construction, or round-off errors. In this case the application of the finite element method results in a system of linear equations with numerous interval parameters which cannot be solved conventionally. Applying a suitable variable substitution, an iteration method for the solution of a parametric system of linear equations is firstly employed to obtain initial bounds on the node displacements. Thereafter, an interval tightening （pruning） technique is applied, firstly on the element forces and secondly on the node displacements, in order to obtain tight guaranteed enclosures for the interval solutions for the forces and displacements.
文摘The cytology of 130 indeterminate nodules （Thy 3） was retrospectively reviewed according to the British Thyroid Association 2014 classification. Nodules were divided into Thy 3a （atypical features） and Thy 3f （follicular lesion） categories. Histology was available as a reference for 97 nodules. Pre-surgical evaluations comprised biochemical tests, color-Doppler ultrasonogrephy （US）, semi-quantitative elastography-US （USE）, contrast-enhanced US （CEUS）, and mutation analysis from cytological slides. Thyroid malignancy was the final diagnosis for 19% of surgically- treated nodules. No statistically significant difference in the risk of malignancy was found between Thy 3a （26%） and Thy 3f （14%） nodules. Histology of the Thy 3a and Thy 3f nodules showed a higher incidence of Hurtle cell adenomas in Thy 3f （29%） than in Thy 3a （3%） nodules （P=0.01）. The only pre-surgical difference concerned the BRAF V600E mutation, which was positive in some Thy 3a but not in any Thy 3f nodules （P=0.04）. Receiver-operating characteristic （ROC） analysis was used to obtain cut-off values from US （score）, USE （ELX 2/1 strain index）, and CEUS （time-to- peak index and peak index） data. The cut-off values were similar for Thy 3a and Thy 3f nodules. Data showed that malignancy can be suspected if the US score is 〉2, ELX 1/2 strain index 〉1, time-to-peakindex 〉1, and peak index 〈1. In a sub-group of 24 revised nodules （12 Thy 3a and 12 Thy 3f） with histology as a reference, the diagnostic power of cumulative pre-surgical analysis by means of US, USE, and CEUS showed high positive and negative predictive values （83% and 100%, respectively） for the presence of malignancy in Thy 3a and Thy 3f nodules. In conclusion, in our series of revised Thy 3 nodules, malignancy was low and displayed no significant differences between Thy 3a and Thy 3f categories. The use of cut-offs based on histology as a reference could reduce surgery. Our data support the conviction that, in mutation-negative Thy 3a and Thy 3f nodules, observation should be the first choice when not all instrumental results are suspect.
基金This work was jointly supported by the National Natural Science Foundation of China under Grant No. 11047114, the Key Project of Chinese Ministry of Education under Grant No. 210141, and the Youth Project of Hubei Education Department under Grant No. Q20101609.
文摘Over the past decades, complex networks have been prosperous greatly in various fields of sciences and engineering. Much attention has been given to investigate the synchronization of complex networks in recent years. However, few work has done for the networks with uncertain parameters and unknown topology. In this paper, to further reveal the dynamical mechanism in complex networks with time delays, an uncertain general complex dynamical network with delayed nodes is studied. By constructing a drive network and a suitable slave network, several novel criteria for the networks consisting of the identical nodes and different nodes have been obtained based on the adaptive feedback method. Particularly, the hypotheses and the proposed adaptive laws for network synchronization are simple and can be readily applied in practical applications. Finally, numerical simulations are provided to illustrate the effectiveness of the proposed synchronization criteria.
