In the process of 2-D compressional wave propagation in a rock mass with multiple parallel joints along the radian direction normal to the joints, the maximum possible wave amplitude corresponding to the points betwee...In the process of 2-D compressional wave propagation in a rock mass with multiple parallel joints along the radian direction normal to the joints, the maximum possible wave amplitude corresponding to the points between the two adjacent joints in the joint set is controlled by superposition of the multiple transmitted and the reflected waves, measured by the maximum rebound ratio. Parametric studies on the maximum rebound ratio along the radian direction normal to the joints were performed in universal distinct element code. The results show that the maximum rebound ratio is influenced by three factors, i.e., the normalized normal stiffness of joints, the ratio of joint spacing to wavelength and the joint from which the wave rebounds. The relationship between the maximum rebound ratio and the influence factors is generalized into five charts. Those charts can be used as the prediction model for estimating the maximum rebound ratio.展开更多
Effects of current density, duty cycle and frequency on microstructure and particles content of electrodeposited Co-BN （hexagonal） nano composite coatings were analyzed by SEM, FESEM, EDS, AFM and XRD techniques. Th...Effects of current density, duty cycle and frequency on microstructure and particles content of electrodeposited Co-BN （hexagonal） nano composite coatings were analyzed by SEM, FESEM, EDS, AFM and XRD techniques. The microhardness, tribological behavior and wear mechanism were also investigated. Generally, as the current density and frequency increased, the particles content and microhardness of the coatings increased firstly and then decreased. Moreover, by reducing duty cycle, more particles were incorporated and higher microhardness was obtained. The best tribological behavior was achieved under the conditions duty cycle of 10%, frequency of 50 Hz and current density of 100 mA/cm2.展开更多
Recently, trimming Soft-output Viterbi algorithm(T-SOVA) has been proposed to reduce the complexity of SOVA for Turbo codes. In its fi rst stage, a dynamic algorithm, lazy Viterbi algorithm, is used to indicate the mi...Recently, trimming Soft-output Viterbi algorithm(T-SOVA) has been proposed to reduce the complexity of SOVA for Turbo codes. In its fi rst stage, a dynamic algorithm, lazy Viterbi algorithm, is used to indicate the minimal metric differences which brings obstacle on hardware implementation. This paper proposes a Viterbi algorithm(VA) based T-SOVA to facilitate hardware implementation. In the first stage of our scheme, a modified VA with regular structure is used to fi nd the maximum likelihood(ML) path and calculate the metric differences. Further, local sorting is introduced to trim the metric differences, which reduces the complexity of trimming operation. Simulation results and complexity analysis show that VA based T-SOVA performs as well as lazy VA based T-SOVA and is easier to be applied to hardware implementation.展开更多
基金Projects(50278057) supported by the National Natural Science Foundation of China project(2002CB412703) supported by Major State Basic Research Development Program of China
文摘In the process of 2-D compressional wave propagation in a rock mass with multiple parallel joints along the radian direction normal to the joints, the maximum possible wave amplitude corresponding to the points between the two adjacent joints in the joint set is controlled by superposition of the multiple transmitted and the reflected waves, measured by the maximum rebound ratio. Parametric studies on the maximum rebound ratio along the radian direction normal to the joints were performed in universal distinct element code. The results show that the maximum rebound ratio is influenced by three factors, i.e., the normalized normal stiffness of joints, the ratio of joint spacing to wavelength and the joint from which the wave rebounds. The relationship between the maximum rebound ratio and the influence factors is generalized into five charts. Those charts can be used as the prediction model for estimating the maximum rebound ratio.
文摘Effects of current density, duty cycle and frequency on microstructure and particles content of electrodeposited Co-BN （hexagonal） nano composite coatings were analyzed by SEM, FESEM, EDS, AFM and XRD techniques. The microhardness, tribological behavior and wear mechanism were also investigated. Generally, as the current density and frequency increased, the particles content and microhardness of the coatings increased firstly and then decreased. Moreover, by reducing duty cycle, more particles were incorporated and higher microhardness was obtained. The best tribological behavior was achieved under the conditions duty cycle of 10%, frequency of 50 Hz and current density of 100 mA/cm2.
基金supported by NSAF under Grant(No.U1530117)National Natural Science Foundation of China(No.61471022)
文摘Recently, trimming Soft-output Viterbi algorithm(T-SOVA) has been proposed to reduce the complexity of SOVA for Turbo codes. In its fi rst stage, a dynamic algorithm, lazy Viterbi algorithm, is used to indicate the minimal metric differences which brings obstacle on hardware implementation. This paper proposes a Viterbi algorithm(VA) based T-SOVA to facilitate hardware implementation. In the first stage of our scheme, a modified VA with regular structure is used to fi nd the maximum likelihood(ML) path and calculate the metric differences. Further, local sorting is introduced to trim the metric differences, which reduces the complexity of trimming operation. Simulation results and complexity analysis show that VA based T-SOVA performs as well as lazy VA based T-SOVA and is easier to be applied to hardware implementation.
