A gated viewing laser radar has an excellent performance in underwater low light level imaging, and it also provides a viable solution to inhibit backscattering. In this paper, a gated viewing imaging system according...A gated viewing laser radar has an excellent performance in underwater low light level imaging, and it also provides a viable solution to inhibit backscattering. In this paper, a gated viewing imaging system according to the demand for real-time imaging is presented, and then the simulation is used to analyze the performance of the real-time gated viewing system. The range accuracy performance is limited by the slice number, the width of gate, the delay time step, the initial delay time, as well as the system noise and atmospheric turbulence. The simulation results indicate that the highest range accuracy can be achieved when the system works with the optimal parameters. Finally, how to choose the optimal parameters has been researched.展开更多
In the current process of university scientific research funding audits,the auditors do not obtain audit evidence in a timely manner,resulting in a lag in audit time;at the same time,there is the possibility that the ...In the current process of university scientific research funding audits,the auditors do not obtain audit evidence in a timely manner,resulting in a lag in audit time;at the same time,there is the possibility that the audit evidence may be tampered with,and the sensitive expenditure cannot be effectively protected.Based on this,this paper proposes an audit scheme for university scientific research funds based on a consortium chain.The scheme saves relevant audit evidence through blockchain and IPFS,which changes the storage method of traditional audit evidence and effectively ensures the integrity,auditability of audit evidence and verifiability,and facilitates real-time auditing.We use Pedersen Commitment and Zero-Knowledge Range Proof to ensure the auditability of sensitive data;use smart contracts to automate auditing to further ensure that auditors can find relevant audit issues in a timely manner;and separate different departments and construct an audit tree through multi-channel technology to ensure the integrity and reliability of data and improve audit efficiency and accuracy.Finally,functional comparison analysis and security analysis show that the scheme in this paper has certain feasibility and robustness.展开更多
The BeiDou-3 global satellite navigation system(BDS-3)provides two radio determination satellite service(RDSS)positioning services for users,i.e.,the traditional RDSS(TRDSS)positioning of the BeiDou-2 regional satelli...The BeiDou-3 global satellite navigation system(BDS-3)provides two radio determination satellite service(RDSS)positioning services for users,i.e.,the traditional RDSS(TRDSS)positioning of the BeiDou-2 regional satellite navigation system,and the comprehensive RDSS(CRDSS)positioning,which integrates the RDSS and radio navigation satellite service.As published studies regarding the RDSS positioning service are few,we analyze and compare the performances of the two RDSS positioning modes.First,we systematically investigate the principles of the TRDSS and CRDSS positioning,and then analyze the evaluation methods in terms of their positioning accuracy,real time,and coverage range.Second,based on the BeiDou RDSS measured data,we evaluate the performances of the TRDSS and CRDSS positioning.Compared with TRDSS positioning,CRDSS positioning exhibits the following:1)A significant increase in positioning accuracy,resulting in error improvement from 8 to 2 m and root mean square improvement from 3.13 to 0.85 m;in other words,the positioning error,constant deviation,and stability improve significantly.2)The real time reduces slightly from 1.1 to 1.8 ns,which is within the acceptable range.3)The coverage range expands from the areas of 62°E-145°E and 5°N-55°N to the areas of 50°E-170°E and 0°N-70°N,respectively.4)CRDSS positioning is not restricted by the constraints of the digital elevation database or the user elevation information and can thus solve the occlusion problem effectively.展开更多
基金supported by the Pre-research Foundation under Grant No. G020104PJ09DZ0246
文摘A gated viewing laser radar has an excellent performance in underwater low light level imaging, and it also provides a viable solution to inhibit backscattering. In this paper, a gated viewing imaging system according to the demand for real-time imaging is presented, and then the simulation is used to analyze the performance of the real-time gated viewing system. The range accuracy performance is limited by the slice number, the width of gate, the delay time step, the initial delay time, as well as the system noise and atmospheric turbulence. The simulation results indicate that the highest range accuracy can be achieved when the system works with the optimal parameters. Finally, how to choose the optimal parameters has been researched.
基金supported by Major Science and Technology Project of Henan Province (project number 20130021030).
文摘In the current process of university scientific research funding audits,the auditors do not obtain audit evidence in a timely manner,resulting in a lag in audit time;at the same time,there is the possibility that the audit evidence may be tampered with,and the sensitive expenditure cannot be effectively protected.Based on this,this paper proposes an audit scheme for university scientific research funds based on a consortium chain.The scheme saves relevant audit evidence through blockchain and IPFS,which changes the storage method of traditional audit evidence and effectively ensures the integrity,auditability of audit evidence and verifiability,and facilitates real-time auditing.We use Pedersen Commitment and Zero-Knowledge Range Proof to ensure the auditability of sensitive data;use smart contracts to automate auditing to further ensure that auditors can find relevant audit issues in a timely manner;and separate different departments and construct an audit tree through multi-channel technology to ensure the integrity and reliability of data and improve audit efficiency and accuracy.Finally,functional comparison analysis and security analysis show that the scheme in this paper has certain feasibility and robustness.
基金the BeiDou Satellite Navigation Center and the National Natural Science Foundation of China(Nos.41874043,61603397,and 41704037).
文摘The BeiDou-3 global satellite navigation system(BDS-3)provides two radio determination satellite service(RDSS)positioning services for users,i.e.,the traditional RDSS(TRDSS)positioning of the BeiDou-2 regional satellite navigation system,and the comprehensive RDSS(CRDSS)positioning,which integrates the RDSS and radio navigation satellite service.As published studies regarding the RDSS positioning service are few,we analyze and compare the performances of the two RDSS positioning modes.First,we systematically investigate the principles of the TRDSS and CRDSS positioning,and then analyze the evaluation methods in terms of their positioning accuracy,real time,and coverage range.Second,based on the BeiDou RDSS measured data,we evaluate the performances of the TRDSS and CRDSS positioning.Compared with TRDSS positioning,CRDSS positioning exhibits the following:1)A significant increase in positioning accuracy,resulting in error improvement from 8 to 2 m and root mean square improvement from 3.13 to 0.85 m;in other words,the positioning error,constant deviation,and stability improve significantly.2)The real time reduces slightly from 1.1 to 1.8 ns,which is within the acceptable range.3)The coverage range expands from the areas of 62°E-145°E and 5°N-55°N to the areas of 50°E-170°E and 0°N-70°N,respectively.4)CRDSS positioning is not restricted by the constraints of the digital elevation database or the user elevation information and can thus solve the occlusion problem effectively.
