In this paper the concepts of the boundary value problem of abstract kinetic equation with the first kind of critical parameter γ 0 and generalized periodic boundary conditions are introduced in a Lebesgue space whic...In this paper the concepts of the boundary value problem of abstract kinetic equation with the first kind of critical parameter γ 0 and generalized periodic boundary conditions are introduced in a Lebesgue space which consists of functions with vector valued in a general Banach space, and then describe the solution of these abstract boundary value problem by the abstract linear integral operator of Volterra type. We call this process the integral operator solving process.展开更多
Considering two atomic qubits initially in Bell states, we send one qubit into a vacuum cavity with two-photon resonance and leave the other one outside. Using quantum information entropy squeezing theory, the time ev...Considering two atomic qubits initially in Bell states, we send one qubit into a vacuum cavity with two-photon resonance and leave the other one outside. Using quantum information entropy squeezing theory, the time evolutions of the entropy squeezing factor of the atomic qubit inside the cavity are discussed for two cases, i.e., before and after rotation and measurement of the atomic qubit outside the cavity. It is shown that the atomic qubit inside the cavity has no entropy squeezing phenomenon and is always in a decoherent state before the operating atomic qubit outside the cavity. However,the periodical entropy squeezing phenomenon emerges and the optimal entropy squeezing state can be prepared for the atomic qubit inside the cavity by adjusting the rotation angle, choosing the interaction time between the atomic qubit and the cavity, controlling the probability amplitudes of subsystem states. Its physical essence is cutting the entanglement between the atomic qubit and its environment, causing the atomic qubit inside the cavity to change from the initial decoherent state into maximum coherent superposition state, which is a possible way of recovering the coherence of a single atomic qubit in the noise environment.展开更多
A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic response...A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.展开更多
A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architectu...A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architecture with positive channel metal oxide semiconductor（PMOS） differential input transistors and sub-threshold technology are applied under the low supply voltage.Simulation results show that this amplifier has significantly low power,while maintaining almost the same gain,bandwidth and other key performances.The power required is only 0.12 mW,which is applicable to low-power and low-voltage real-time signal acquisition and processing system.展开更多
We investigate how displaced thermal states （DTSs） evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly ...We investigate how displaced thermal states （DTSs） evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly classical thermal field only related to the laser parameters κ and g. The normal ordering product of density operator of the DTS in the laser channel leads to obtaining the analytical time-evolution expressions of the photon number, Wigner function, and von Neumann entropy. Also, some interesting results are presented via numerically investigating these explicit time-dependent expressions.展开更多
The performance analysis of the generalized Carlson iterating process,which can realize the rational approximation of fractional operator with arbitrary order,is presented in this paper.The reasons why the generalized...The performance analysis of the generalized Carlson iterating process,which can realize the rational approximation of fractional operator with arbitrary order,is presented in this paper.The reasons why the generalized Carlson iterating function possesses more excellent properties such as self-similarity and exponential symmetry are also explained.K-index,P-index,O-index,and complexity index are introduced to contribute to performance analysis.Considering nine different operational orders and choosing an appropriate rational initial impedance for a certain operational order,these rational approximation impedance functions calculated by the iterating function meet computational rationality,positive reality,and operational validity.Then they are capable of having the operational performance of fractional operators and being physical realization.The approximation performance of the impedance function to the ideal fractional operator and the circuit network complexity are also exhibited.展开更多
In recent years,marine pilotage accidents occurring on a worldwide basis as a result of human error have not been ceased to transpire,despite advances in technology and a significant set of international conventions,r...In recent years,marine pilotage accidents occurring on a worldwide basis as a result of human error have not been ceased to transpire,despite advances in technology and a significant set of international conventions,regulations,and recommendations to reduce them.This paper aims to investigate the effect of human factors on the safety of maritime pilotage operations.The human factors that affect the operators who are performing ships’berthing operations have also been examined in detail.In this study,in order to determine the causes of human-related errors occurred in maritime pilotage accidents,a comprehensive literature review is carried out,and a considerable number of real past case examples and an analysis of the maritime accident investigation reports regarding pilotage operations events that occurred between 1995 and 2015 have been reviewed.To validate the identified humanrelated risk factors(HCFs)and explore other contributory factors,survey questionnaires and semi-structured interviews with domain experts have been conducted.A structural hierarchy diagram for the identified risk factors(HCFs)has been developed and validated through experienced experts belonging to the maritime sector.A questionnaire for pair-wise comparison is carried out and analysed using the analytic hierarchy process(AHP)approach to evaluate the weight and rank the importance of the identified human causal factors.The findings of this study will benefit the maritime industry,by identifying a new database on causal factors that are contributing to the occurrence of maritime pilotage disasters.The database can be used as a stand-alone reference or help implement effective risk reduction strategies to reduce the human error,that might occur during pilotage operations.展开更多
This article mainly refers to a brief introduction on the design and operation of resid hydrogenation units in China's Mainland in order to keep the peers abreast of the basic status of aoolication of resid hydrog...This article mainly refers to a brief introduction on the design and operation of resid hydrogenation units in China's Mainland in order to keep the peers abreast of the basic status of aoolication of resid hydrogenation process in the China's Mainland.展开更多
With the increasing civil aviation passengers and the rapid development of aviation logistics,the study on remotely piloted operation(RPO)mode has received extensive attention.RPO mode constructs the piloting decision...With the increasing civil aviation passengers and the rapid development of aviation logistics,the study on remotely piloted operation(RPO)mode has received extensive attention.RPO mode constructs the piloting decisionmaking mode which involves the tripartite collaboration among airborne automatic/autonomous system,remote ground-based crews and air traffic control.In this paper,we describe the organizing architecture for commercial remotely piloted aircraft(CRPA)system and its components.Compared with the current operation mode,the new air-ground collaborative decision-making mode has been established with six different situations based on the type of the flight and the condition of the remote pilot.Taking airport surface operation as an experimental example,we model the airport surface operation process and compare the advantages and disadvantages between RPO mode and the current dual-pilot mode from the perspectives of time and operation coverage,and draw conclusions that RPO mode can basically cover the flight operations of the dual-pilot,improve the accuracy of pilot operations and greatly reduce response time by 48%in pre-flight inspection.The above research would be the foundation for the RPO development of commercial aircraft in China.展开更多
1. Introduction In quantum optics, optical frequency conversion is a typical nonlinear process and is worth studying, for example, a second harmonic frequency generation will generate a squeezed state.[1＇2l In this ...1. Introduction In quantum optics, optical frequency conversion is a typical nonlinear process and is worth studying, for example, a second harmonic frequency generation will generate a squeezed state.[1＇2l In this work, we tackle the evolution of an initial coherent state in a Raman dispersion process which is also a nonlinear process. The process involves the inelastic scattering of a pho- ton when it is incident on a molecule. The photon loses some of its energy to the molecule or gains some from it, and so leaves the molecule with a lower or a higher frequency. The lower frequency components of the scattered radiation are called the Stokes lines and the higher frequency components are called the anti- Stokes lines. The Hamiltonian governing its dynamics is[3]展开更多
Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal a...Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers （op-amps）. The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup.展开更多
Using the well-behaved features of the thermal entangled state representation, we solve the diffusion master equation under the action of a linear resonance force, and then obtain the infinitive operator-sum represent...Using the well-behaved features of the thermal entangled state representation, we solve the diffusion master equation under the action of a linear resonance force, and then obtain the infinitive operator-sum representation of the density operator. This approach may also be effective for treating other master equations. Moreover, we find that the initial pure coherent state evolves into a mixed thermal state after passing through the diffusion process under the action of the linear resonance force.展开更多
(Multichannel)Singular spectrum analysis is considered as one of the most effective methods for seismic incoherent noise suppression.It utilizes the low-rank feature of seismic signal and regards the noise suppression...(Multichannel)Singular spectrum analysis is considered as one of the most effective methods for seismic incoherent noise suppression.It utilizes the low-rank feature of seismic signal and regards the noise suppression as a low-rank reconstruction problem.However,in some cases the seismic geophones receive some erratic disturbances and the amplitudes are dramatically larger than other receivers.The presence of this kind of noise,called erratic noise,makes singular spectrum analysis(SSA)reconstruction unstable and has undesirable effects on the final results.We robustify the low-rank reconstruction of seismic data by a reweighted damped SSA(RD-SSA)method.It incorporates the damped SSA,an improved version of SSA,into a reweighted framework.The damping operator is used to weaken the artificial disturbance introduced by the low-rank projection of both erratic and random noise.The central idea of the RD-SSA method is to iteratively approximate the observed data with the quadratic norm for the first iteration and the Tukeys bisquare norm for the rest iterations.The RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic disturbance.The feasibility of RD-SSA is validated via both synthetic and field data examples.展开更多
文摘In this paper the concepts of the boundary value problem of abstract kinetic equation with the first kind of critical parameter γ 0 and generalized periodic boundary conditions are introduced in a Lebesgue space which consists of functions with vector valued in a general Banach space, and then describe the solution of these abstract boundary value problem by the abstract linear integral operator of Volterra type. We call this process the integral operator solving process.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374096 and 11405052)
文摘Considering two atomic qubits initially in Bell states, we send one qubit into a vacuum cavity with two-photon resonance and leave the other one outside. Using quantum information entropy squeezing theory, the time evolutions of the entropy squeezing factor of the atomic qubit inside the cavity are discussed for two cases, i.e., before and after rotation and measurement of the atomic qubit outside the cavity. It is shown that the atomic qubit inside the cavity has no entropy squeezing phenomenon and is always in a decoherent state before the operating atomic qubit outside the cavity. However,the periodical entropy squeezing phenomenon emerges and the optimal entropy squeezing state can be prepared for the atomic qubit inside the cavity by adjusting the rotation angle, choosing the interaction time between the atomic qubit and the cavity, controlling the probability amplitudes of subsystem states. Its physical essence is cutting the entanglement between the atomic qubit and its environment, causing the atomic qubit inside the cavity to change from the initial decoherent state into maximum coherent superposition state, which is a possible way of recovering the coherence of a single atomic qubit in the noise environment.
基金Supported by the National Natural Science Foundation of China（51079027）
文摘A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.
基金Sponsored by the National Natural Science Foundation of China (60843005)the Basic Research Foundation of Beijing Institute of Technology(20070142018)
文摘A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architecture with positive channel metal oxide semiconductor（PMOS） differential input transistors and sub-threshold technology are applied under the low supply voltage.Simulation results show that this amplifier has significantly low power,while maintaining almost the same gain,bandwidth and other key performances.The power required is only 0.12 mW,which is applicable to low-power and low-voltage real-time signal acquisition and processing system.
基金Project supported by the National Natural Science Foundation of China(Grant No.11347026)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2016AM03 and ZR2017MA011)
文摘We investigate how displaced thermal states （DTSs） evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly classical thermal field only related to the laser parameters κ and g. The normal ordering product of density operator of the DTS in the laser channel leads to obtaining the analytical time-evolution expressions of the photon number, Wigner function, and von Neumann entropy. Also, some interesting results are presented via numerically investigating these explicit time-dependent expressions.
文摘The performance analysis of the generalized Carlson iterating process,which can realize the rational approximation of fractional operator with arbitrary order,is presented in this paper.The reasons why the generalized Carlson iterating function possesses more excellent properties such as self-similarity and exponential symmetry are also explained.K-index,P-index,O-index,and complexity index are introduced to contribute to performance analysis.Considering nine different operational orders and choosing an appropriate rational initial impedance for a certain operational order,these rational approximation impedance functions calculated by the iterating function meet computational rationality,positive reality,and operational validity.Then they are capable of having the operational performance of fractional operators and being physical realization.The approximation performance of the impedance function to the ideal fractional operator and the circuit network complexity are also exhibited.
文摘In recent years,marine pilotage accidents occurring on a worldwide basis as a result of human error have not been ceased to transpire,despite advances in technology and a significant set of international conventions,regulations,and recommendations to reduce them.This paper aims to investigate the effect of human factors on the safety of maritime pilotage operations.The human factors that affect the operators who are performing ships’berthing operations have also been examined in detail.In this study,in order to determine the causes of human-related errors occurred in maritime pilotage accidents,a comprehensive literature review is carried out,and a considerable number of real past case examples and an analysis of the maritime accident investigation reports regarding pilotage operations events that occurred between 1995 and 2015 have been reviewed.To validate the identified humanrelated risk factors(HCFs)and explore other contributory factors,survey questionnaires and semi-structured interviews with domain experts have been conducted.A structural hierarchy diagram for the identified risk factors(HCFs)has been developed and validated through experienced experts belonging to the maritime sector.A questionnaire for pair-wise comparison is carried out and analysed using the analytic hierarchy process(AHP)approach to evaluate the weight and rank the importance of the identified human causal factors.The findings of this study will benefit the maritime industry,by identifying a new database on causal factors that are contributing to the occurrence of maritime pilotage disasters.The database can be used as a stand-alone reference or help implement effective risk reduction strategies to reduce the human error,that might occur during pilotage operations.
文摘This article mainly refers to a brief introduction on the design and operation of resid hydrogenation units in China's Mainland in order to keep the peers abreast of the basic status of aoolication of resid hydrogenation process in the China's Mainland.
基金supported by the National Program on Key Basic Research Project (No. 2014CB744903)the National Natural Science Foundation of China(Nos. 61973212,61673270)+3 种基金the Shanghai Industrial Strengthening Project (No. GYQJ-2017-5-08)the Shanghai Science and Technology Committee Research Project (No. 17DZ1204304)the Civil Aviation Pre-Research ProjectsShanghai Engineering Research Center of Civil Aircraft Flight Testing.
文摘With the increasing civil aviation passengers and the rapid development of aviation logistics,the study on remotely piloted operation(RPO)mode has received extensive attention.RPO mode constructs the piloting decisionmaking mode which involves the tripartite collaboration among airborne automatic/autonomous system,remote ground-based crews and air traffic control.In this paper,we describe the organizing architecture for commercial remotely piloted aircraft(CRPA)system and its components.Compared with the current operation mode,the new air-ground collaborative decision-making mode has been established with six different situations based on the type of the flight and the condition of the remote pilot.Taking airport surface operation as an experimental example,we model the airport surface operation process and compare the advantages and disadvantages between RPO mode and the current dual-pilot mode from the perspectives of time and operation coverage,and draw conclusions that RPO mode can basically cover the flight operations of the dual-pilot,improve the accuracy of pilot operations and greatly reduce response time by 48%in pre-flight inspection.The above research would be the foundation for the RPO development of commercial aircraft in China.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10775097 and 10475056)
文摘1. Introduction In quantum optics, optical frequency conversion is a typical nonlinear process and is worth studying, for example, a second harmonic frequency generation will generate a squeezed state.[1＇2l In this work, we tackle the evolution of an initial coherent state in a Raman dispersion process which is also a nonlinear process. The process involves the inelastic scattering of a pho- ton when it is incident on a molecule. The photon loses some of its energy to the molecule or gains some from it, and so leaves the molecule with a lower or a higher frequency. The lower frequency components of the scattered radiation are called the Stokes lines and the higher frequency components are called the anti- Stokes lines. The Hamiltonian governing its dynamics is[3]
文摘Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers （op-amps）. The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup.
基金supported by the National Natural Science Foundation of China(Grant Nos.11347026,11147009,and 11244005)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2013AM012 and ZR2012AM004)the Scientific Research Project of Liaocheng,China
文摘Using the well-behaved features of the thermal entangled state representation, we solve the diffusion master equation under the action of a linear resonance force, and then obtain the infinitive operator-sum representation of the density operator. This approach may also be effective for treating other master equations. Moreover, we find that the initial pure coherent state evolves into a mixed thermal state after passing through the diffusion process under the action of the linear resonance force.
基金supported by the National Natural Science Foundation of China under grant no.42374133the Beijing Nova Program under grant no.2022056+1 种基金the Fundamental Research Funds for the Central Universities under grant no.2462020YXZZ006the Young Elite Scientists Sponsorship Program by CAST(YESS)under grant no.2018QNRC001。
文摘(Multichannel)Singular spectrum analysis is considered as one of the most effective methods for seismic incoherent noise suppression.It utilizes the low-rank feature of seismic signal and regards the noise suppression as a low-rank reconstruction problem.However,in some cases the seismic geophones receive some erratic disturbances and the amplitudes are dramatically larger than other receivers.The presence of this kind of noise,called erratic noise,makes singular spectrum analysis(SSA)reconstruction unstable and has undesirable effects on the final results.We robustify the low-rank reconstruction of seismic data by a reweighted damped SSA(RD-SSA)method.It incorporates the damped SSA,an improved version of SSA,into a reweighted framework.The damping operator is used to weaken the artificial disturbance introduced by the low-rank projection of both erratic and random noise.The central idea of the RD-SSA method is to iteratively approximate the observed data with the quadratic norm for the first iteration and the Tukeys bisquare norm for the rest iterations.The RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic disturbance.The feasibility of RD-SSA is validated via both synthetic and field data examples.
