A rigorous analytical method is presented, which takes into account the pile stiffening effects, using the theory of the transfer matrix-bottom rigidity for calculating the interaction factor between two identical pil...A rigorous analytical method is presented, which takes into account the pile stiffening effects, using the theory of the transfer matrix-bottom rigidity for calculating the interaction factor between two identical piles in multi-layered soils subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decomposed into extended soil layers and two fictitious piles characterized respectively by Young's moduli of the layered soils and those of the differences between the piles and the layered soils. The unknown axial forces along fictitious piles are determined by solving a Fredholm integral equation of the second kind, which imposes the compatibility condition that the axial strains of the fictitious piles are equal to those corresponding to the centroidal axes of the extended layered soils. The real pile displacements can be calculated based on the determined fictitious pile forces, and finally, the desired pile interaction factors may be obtained. Selected results from parametrical studies are presented to confirm the validity of the proposed approach and portray the influence of the governing parameters on the pile interaction.展开更多
In order to obtain the primary parameters and operating characteristics of a DC motor without directly measuring its torque and rational speed, it is proposed to use a PC and a data acquisition card to acquire both th...In order to obtain the primary parameters and operating characteristics of a DC motor without directly measuring its torque and rational speed, it is proposed to use a PC and a data acquisition card to acquire both the dynamic and static data of armature current to establish the performance of a DC permanent magnet motor. The accuracy and validity of this virtual test system proposed were verified by comparing the measurements made with the system proposed with the measurements made with conventional torque meters. It is concluded from the results of comparison that from the mathematic model established for the DC permant magnet motors, both major parameters and operating characteristics can be directly established for the DC motors without measuring their torques and rotational speed, a perfect on line measurement and test system has been established for the DC permanent magnet motors using the theory of virtual test system. The system proposed features shorter test time, higher efficiency and lower cost.展开更多
The diagnostic value of virtual colonoscopy versus colonoscopy was compared in detection of colorectal neoplasia. Virtual colonoscopy was performed on 29 patients with suspected colorectal diseases, Results were compa...The diagnostic value of virtual colonoscopy versus colonoscopy was compared in detection of colorectal neoplasia. Virtual colonoscopy was performed on 29 patients with suspected colorectal diseases, Results were compared with colonoscopy for each case. Virtual colonoscopy was successfully performed on each patient. All patients tolerated virtual colonoscopy well, had no complications. All colorectal malignance were identified both by virtual colonoscopy and colonoscopy. Twenty-five polyps were detected with colonoscopy, whereas only 16 polyps were defined by virtual colonoscopy. Detection rates of polyps greater than 1.0 cm,between 0.5-0.9 cm and less than 0.5 cm in size were 90%,62.5% and 28.6% respectively. Virtual colonoscopy is fast, minimally invasive and well tolerated. This technique is a valuable clinical method in diagnosis of colorectal malignance and polyps larger than 0.5 cm in size.展开更多
Intuitionistic fuzzy sets are generalized fuzzy sets which were first introduced by Atanassov in 1986. In this paper, we introduce the concept of intuitionistic fuzzy M-subsemigroups of an M-semigroup M with respect t...Intuitionistic fuzzy sets are generalized fuzzy sets which were first introduced by Atanassov in 1986. In this paper, we introduce the concept of intuitionistic fuzzy M-subsemigroups of an M-semigroup M with respect to an s-norm S and a t-norm T on in-tuitionistic fuzzy sets and study their properties. In particular, intuitionistic （S,T）-direct products of M-semigroups are considered and some recent results of fuzzy M-subsemigroups of M-semigroups obtained by Zhan and Tan^[21] are extended and generalized to intuitionistic （S, T）-fuzzy M-subsemigroups over M-semigroups.展开更多
基金National Natural Science Foundation of China(No.50478022)Research and Innovation Project of Shanghai Education Committee,China(No.10YZ208)Excellent Young Teacher Project of Shanghai Education Committee,China(No.dsd08005)
文摘A rigorous analytical method is presented, which takes into account the pile stiffening effects, using the theory of the transfer matrix-bottom rigidity for calculating the interaction factor between two identical piles in multi-layered soils subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decomposed into extended soil layers and two fictitious piles characterized respectively by Young's moduli of the layered soils and those of the differences between the piles and the layered soils. The unknown axial forces along fictitious piles are determined by solving a Fredholm integral equation of the second kind, which imposes the compatibility condition that the axial strains of the fictitious piles are equal to those corresponding to the centroidal axes of the extended layered soils. The real pile displacements can be calculated based on the determined fictitious pile forces, and finally, the desired pile interaction factors may be obtained. Selected results from parametrical studies are presented to confirm the validity of the proposed approach and portray the influence of the governing parameters on the pile interaction.
文摘In order to obtain the primary parameters and operating characteristics of a DC motor without directly measuring its torque and rational speed, it is proposed to use a PC and a data acquisition card to acquire both the dynamic and static data of armature current to establish the performance of a DC permanent magnet motor. The accuracy and validity of this virtual test system proposed were verified by comparing the measurements made with the system proposed with the measurements made with conventional torque meters. It is concluded from the results of comparison that from the mathematic model established for the DC permant magnet motors, both major parameters and operating characteristics can be directly established for the DC motors without measuring their torques and rotational speed, a perfect on line measurement and test system has been established for the DC permanent magnet motors using the theory of virtual test system. The system proposed features shorter test time, higher efficiency and lower cost.
文摘The diagnostic value of virtual colonoscopy versus colonoscopy was compared in detection of colorectal neoplasia. Virtual colonoscopy was performed on 29 patients with suspected colorectal diseases, Results were compared with colonoscopy for each case. Virtual colonoscopy was successfully performed on each patient. All patients tolerated virtual colonoscopy well, had no complications. All colorectal malignance were identified both by virtual colonoscopy and colonoscopy. Twenty-five polyps were detected with colonoscopy, whereas only 16 polyps were defined by virtual colonoscopy. Detection rates of polyps greater than 1.0 cm,between 0.5-0.9 cm and less than 0.5 cm in size were 90%,62.5% and 28.6% respectively. Virtual colonoscopy is fast, minimally invasive and well tolerated. This technique is a valuable clinical method in diagnosis of colorectal malignance and polyps larger than 0.5 cm in size.
基金the National Natural Science Foundation of China(60474022)the Key Science Foundation of Education Committee of Hubei Province(2004Z002D200529001).
文摘Intuitionistic fuzzy sets are generalized fuzzy sets which were first introduced by Atanassov in 1986. In this paper, we introduce the concept of intuitionistic fuzzy M-subsemigroups of an M-semigroup M with respect to an s-norm S and a t-norm T on in-tuitionistic fuzzy sets and study their properties. In particular, intuitionistic （S,T）-direct products of M-semigroups are considered and some recent results of fuzzy M-subsemigroups of M-semigroups obtained by Zhan and Tan^[21] are extended and generalized to intuitionistic （S, T）-fuzzy M-subsemigroups over M-semigroups.
