In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular,...In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model.展开更多
The level surfaces of geometric discord for a class of two-qubit non-X states are investigated when the Bloch vectors are in arbitrary directions. The level surfaces of constant geometric discord are formed by three i...The level surfaces of geometric discord for a class of two-qubit non-X states are investigated when the Bloch vectors are in arbitrary directions. The level surfaces of constant geometric discord are formed by three intersecting open tubes along three orthogc^nal directions. When Bloch vectors increase, the tubes along one or two directions shrink towards the center and may either totally disappear or the open tubes may become closed tubes when the Bloch vectors reach a critical value. In the generalized amplitude damping channel, the evolution of geometric discord shows double sudden changes when the parameter γ, increases. In the phase damping channel, the freezing phenomenon of geometric discord also exists.展开更多
The Holevo capacity of a generalized amplitude-damping channel is investigated by using a numerical method. It is shown that the Holevo capacity depends on the channel parameters representing the ambient temperature a...The Holevo capacity of a generalized amplitude-damping channel is investigated by using a numerical method. It is shown that the Holevo capacity depends on the channel parameters representing the ambient temperature and fidelity. In particular, under a special condition, the Holevo capacity of the generalized amplitude-damping channel can be written as an analytical expression.展开更多
The problem of sending a single classical bit through a generalized amplitude damping channel is considered. When two transmissions through the channel arc available as a resource, we find that two entangled transmiss...The problem of sending a single classical bit through a generalized amplitude damping channel is considered. When two transmissions through the channel arc available as a resource, we find that two entangled transmissions can enhance the capability of receiver＇s judging information correctly under certain conditions compared with two productstate transmissions. In addition, we find a special case in which the two entangled transmissions can always make a classical bit more effectively disable the noise influence.展开更多
To clarify the internal flow field characteristics of cavity vortex in the sediment transport pipe(STP)of the desilting channel with a swirling flow generator(DCSFG),this study adopted a method combining model test,nu...To clarify the internal flow field characteristics of cavity vortex in the sediment transport pipe(STP)of the desilting channel with a swirling flow generator(DCSFG),this study adopted a method combining model test,numerical simulation,and theoretical analysis to investigate flow field characteristics such as water flow regime,cavity morphology,pressure,flow velocity and vorticity,analyze the distribution of combined vortex indexes and radial pressure difference of cavity vortex,and discuss the motion feature differences between the combined vortex in the cavity vortex and the ideal combined vortex.The results show that large eddy simulation(LES)exhibits higher accuracy than the Realizable k-ε model,the distribution of combined vortex n values along typical cross-sections inside the STP ranges from -0.901 to 0.913 radially,indicating quasi-forced vortex motion on the inner side of the vortex area and quasi-free vortex motion on the outer side,the theoretical values of radial pressure difference align well with the simulation results,with a maximum relative error of 15%,confirming that the flow characteristics of the vortex are in accordance with the motion features of combined vortex,the distribution of radial pressure,tangential velocity,and vorticity in the cavity vortex conform to the distribution pattern of ideal combined vortex,whereas significant differences exist in terms of fluid force conditions,structural composition,and generation mechanism.The research findings may provide reference for further analyzing the sediment transport mechanism in the cavity vortex and for the practical engineering design and application of the DCSFG.展开更多
基金supported by the Fundamental Research Funds for the Center University of China under Grant HIT. MKSTISP. 2016 13
文摘In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model.
基金supported by the National Natural Science Foundation of China(Grant Nos.11074184,11204197,and 11105095)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20103201120002)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘The level surfaces of geometric discord for a class of two-qubit non-X states are investigated when the Bloch vectors are in arbitrary directions. The level surfaces of constant geometric discord are formed by three intersecting open tubes along three orthogc^nal directions. When Bloch vectors increase, the tubes along one or two directions shrink towards the center and may either totally disappear or the open tubes may become closed tubes when the Bloch vectors reach a critical value. In the generalized amplitude damping channel, the evolution of geometric discord shows double sudden changes when the parameter γ, increases. In the phase damping channel, the freezing phenomenon of geometric discord also exists.
基金Project supported by the National Natural Science Foundation of China （Grant No 10374025）, and the Natural Science Foundation of Hunan Normal University, China （Grant No 22040640）.
文摘The Holevo capacity of a generalized amplitude-damping channel is investigated by using a numerical method. It is shown that the Holevo capacity depends on the channel parameters representing the ambient temperature and fidelity. In particular, under a special condition, the Holevo capacity of the generalized amplitude-damping channel can be written as an analytical expression.
基金Project supported by the National Natural Science Foundation of China （Grant No 10374025）, the Natural Science Foundation of Hunan Normal University （Grant No 22040640） and the Natural Science Foundation of Hunan Province （Grant No 03jjy3012）.
文摘The problem of sending a single classical bit through a generalized amplitude damping channel is considered. When two transmissions through the channel arc available as a resource, we find that two entangled transmissions can enhance the capability of receiver＇s judging information correctly under certain conditions compared with two productstate transmissions. In addition, we find a special case in which the two entangled transmissions can always make a classical bit more effectively disable the noise influence.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52069011),the Youth Science and Technology Talent Innovation Project of Lanzhou(Grant No.2023-QN-33).
文摘To clarify the internal flow field characteristics of cavity vortex in the sediment transport pipe(STP)of the desilting channel with a swirling flow generator(DCSFG),this study adopted a method combining model test,numerical simulation,and theoretical analysis to investigate flow field characteristics such as water flow regime,cavity morphology,pressure,flow velocity and vorticity,analyze the distribution of combined vortex indexes and radial pressure difference of cavity vortex,and discuss the motion feature differences between the combined vortex in the cavity vortex and the ideal combined vortex.The results show that large eddy simulation(LES)exhibits higher accuracy than the Realizable k-ε model,the distribution of combined vortex n values along typical cross-sections inside the STP ranges from -0.901 to 0.913 radially,indicating quasi-forced vortex motion on the inner side of the vortex area and quasi-free vortex motion on the outer side,the theoretical values of radial pressure difference align well with the simulation results,with a maximum relative error of 15%,confirming that the flow characteristics of the vortex are in accordance with the motion features of combined vortex,the distribution of radial pressure,tangential velocity,and vorticity in the cavity vortex conform to the distribution pattern of ideal combined vortex,whereas significant differences exist in terms of fluid force conditions,structural composition,and generation mechanism.The research findings may provide reference for further analyzing the sediment transport mechanism in the cavity vortex and for the practical engineering design and application of the DCSFG.
