For the vector attitude determination, the traditional optimal algorithms which are based on quaternion estimator（QUEST） measurement noise model are complicated for just two observations. In our application, the mag...For the vector attitude determination, the traditional optimal algorithms which are based on quaternion estimator（QUEST） measurement noise model are complicated for just two observations. In our application, the magnetometer and accelerometer are not two comparable kinds of sensors and both are not small field-of-view sensors as well. So in this paper a new unit measurement model is derived. According to the Wahba problem, the optimal weights for each measurement are obtained by the error variance researches. Then an improved quaternion Gauss–Newton method is presented and adopted to acquire attitude. Eventually, simulation results and experimental validation employed to test the proposed method demonstrate the usefulness of the improved algorithm.展开更多
At present, most underwater positioning algorithms improve the positioning accuracy by increasing the number of anchor nodes which resulting in the increasing energy consumption. To solve this problem, the paper propo...At present, most underwater positioning algorithms improve the positioning accuracy by increasing the number of anchor nodes which resulting in the increasing energy consumption. To solve this problem, the paper proposes a localization algorithm assisted by mobile anchor node and based on region determination(LMRD), which not only improves the positioning accuracy of nodes positioning but also reduces the energy consumption. This algorithm is divided into two stages: region determination stage and location positioning stage. In the region determination stage, the target region is divided into several sub-regions by the region division strategy with the smallest overlap rate which can reduce the number of virtual anchor nodes and lock the target node to a sub-region, and then through the planning of mobile nodes to optimize the travel path, reduce the moving distance, and reduce system energy consumption. In the location positioning stage, the target node location can be calculated using the HILBERT path planning and trilateration. The simulation results show that the proposed algorithm can improve the positioning accuracy when the energy consumption is reduced.展开更多
A new error analysis method is presented via genetic algorithms for high precise heading determination model based on two total positioning stations （TPSs）. The method has the ability to search all possible solution...A new error analysis method is presented via genetic algorithms for high precise heading determination model based on two total positioning stations （TPSs）. The method has the ability to search all possible solution space by the genetic operators of elitist model and restriction. The result of analyzing the error of this model shows that the accuracy of this model is precise enough to meet the need of calibration for navigation systems on ship, and the search space is only 0. 03% of the total search space, and the precision of heading determination is 4＂ in a general dock.展开更多
The underlying principle of pitch determination based on the mean shift algorithm is studied, and the cause of pitch error propagation in the original pseudo code is analyzed. The problem of error propagation is solve...The underlying principle of pitch determination based on the mean shift algorithm is studied, and the cause of pitch error propagation in the original pseudo code is analyzed. The problem of error propagation is solved by choosing an appropriate initial pitch candidate F00. The theoretical choice guideline in a pitch epoch is obtained as ensuring the true pitch F0 satisfying F00/2 〈 F0 〈 3F00/2. The validity of the choice guideline is verified by the F00 experiment. Meanwhile, the algorithm is extended to the pitch determination in the noisy case and compared with the method of subharmonic-to-harmonic ratio （SHR）. The experimental results show that the improved algorithm bears comparison with SHR and it runs much faster than SHR.展开更多
The algorithm of autonomous orbit determination for the probe around small body is studied. In the algorithm, first, the observed images of the body are compared with its pre-computed model of the body to obtain the l...The algorithm of autonomous orbit determination for the probe around small body is studied. In the algorithm, first, the observed images of the body are compared with its pre-computed model of the body to obtain the location of the limb features of the body in the inertial coordinate. Second, the information of the images and features in utilized to obtain the position of the probe using the Levenberg-Marquardt algorithm. The position is then input to an extended Kalman filter which determines the real time orbit of the probe. Finally, considering the effective of the irregular small body shape perturbation and the small body model parameter error on the orbit determination precise, the procedure of autonomous orbit determination is validated using digital simulation.展开更多
This paper presents an optimization model for the location and capacity of electric vehicle(EV)charging stations.The model takes the multiple factors of the“vehicle-station-grid”system into account.Then,ArcScene is ...This paper presents an optimization model for the location and capacity of electric vehicle(EV)charging stations.The model takes the multiple factors of the“vehicle-station-grid”system into account.Then,ArcScene is used to couple the road and power grid models and ensure that the coupling system is strictly under the goal of minimizing the total social cost,which includes the operator cost,user charging cost,and power grid loss.An immune particle swarm optimization algorithm(IPSOA)is proposed in this paper to obtain the optimal coupling strategy.The simulation results show that the algorithm has good convergence and performs well in solving multi-modal problems.It also balances the interests of users,operators,and the power grid.Compared with other schemes,the grid loss cost is reduced by 11.1%and 17.8%,and the total social cost decreases by 9.96%and 3.22%.展开更多
The accuracy of angles-only initial orbit determination(IOD)is significantly compromised when only a short-arc orbit is observed.The ill-conditioned problem in matrices due to weak geometric constraints caused by shor...The accuracy of angles-only initial orbit determination(IOD)is significantly compromised when only a short-arc orbit is observed.The ill-conditioned problem in matrices due to weak geometric constraints caused by short arcs and observation errors typically causes significant errors in the estimated ranges and thus unsatisfactory IOD.This paper presents a critical analysis of the ill-conditioned problem using the Gooding algorithm and proposes several techniques to improve it.On the basis of multiple observations,a least-squares method is proposed to solve the ranges at the first and last epochs.For the short-arc case,the ridge estimation technique is applied to mitigate the ill-conditioned problem.To determine whether an orbit is eccentric,a procedure to assess orbit eccentricity is developed via the range-search method,which aims to provide reasonably accurate initial ranges to the Gooding algorithm.Finally,an eccentricity-constraint technique for the Gooding algorithm is proposed for cases where the orbit is determined to be nearly circular.The performances of these techniques on space-based simulation data are assessed,and an improved Gooding algorithm(I-Gooding)suitable for various observation conditions is proposed.The I-Gooding algorithm is subsequently applied to process actual ground-based observations.The results show that its accuracy in estimating the semimajor axis is 47%higher than that afforded by the standard Gooding algorithm.展开更多
An improved hybrid Time of Arrival (ToA)/ Angle of Arrival (AoA) location algorithm by adopting Gauss-Newton iterative algorithm is proposed. It is with the advantage of fast convergence and combining with the grid-se...An improved hybrid Time of Arrival (ToA)/ Angle of Arrival (AoA) location algorithm by adopting Gauss-Newton iterative algorithm is proposed. It is with the advantage of fast convergence and combining with the grid-search-based method to optimize the initial object coordinates of the iteration, meanwhile, under the condition of small measurement errors caused by noises of ToA and AoA, the algorithm performance can be improved effectively. In the Non-Line-of-Sight (NLoS) environments of the Wireless Sensor Network (WSN), simulation results show that improved accuracy is gained with moderate flexibility and fast steady convergence compared with the existing algorithms.展开更多
Considering the situation that the least-squares(LS)method for system identification has poor robustness and the least absolute deviation(LAD)algorithm is hard to construct,an approximate least absolute deviation(ALAD...Considering the situation that the least-squares(LS)method for system identification has poor robustness and the least absolute deviation(LAD)algorithm is hard to construct,an approximate least absolute deviation(ALAD)algorithm is proposed in this paper.The objective function of ALAD is constructed by introducing a deterministic function to approximate the absolute value function.Based on the function,the recursive equations for parameter identification are derived using Gauss-Newton iterative algorithm without any simplification.This algorithm has advantages of simple calculation and easy implementation,and it has second order convergence speed.Compared with the LS method,the new algorithm has better robustness when disorder and peak noises exist in the measured data.Simulation results show the efficiency of the proposed method.展开更多
Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of 2021.Considering that Turkey announced...Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of 2021.Considering that Turkey announced the Turkish Lira Overnight Reference Interest Rate(TLREF),this study examines the determinants of TLREF.In this context,three global determinants,five country-level macroeconomic determinants,and the COVID-19 pandemic are considered by using daily data between December 28,2018,and December 31,2020,by performing machine learning algorithms and Ordinary Least Square.The empirical results show that(1)the most significant determinant is the amount of securities bought by Central Banks;(2)country-level macroeconomic factors have a higher impact whereas global factors are less important,and the pandemic does not have a significant effect;(3)Random Forest is the most accurate prediction model.Taking action by considering the study’s findings can help support economic growth by achieving low-level benchmark rates.展开更多
Considering the pivotal role of single-wavelength anomalous diffraction(SAD) in macromolecular crystallography,our objective was to introduce DSAS,a novel program designed for efficient anomalous scattering substructu...Considering the pivotal role of single-wavelength anomalous diffraction(SAD) in macromolecular crystallography,our objective was to introduce DSAS,a novel program designed for efficient anomalous scattering substructure determination.DSAS stands out with its core components:a modified phase-retrieval algorithm and automated parameter tuning.The software boasts an intuitive graphical user interface(GUI),facilitating seamless input of essential data and real-time monitoring.Extensive testing on DSAS has involved diverse datasets,encompassing proteins,nucleic acids,and various anomalous scatters such as sulfur(S),selenium(Se),metals,and halogens.The results confirm DSAS’s exceptional performance in accurately determining heavy atom positions,making it a highly effective tool in the field.展开更多
This paper developed an improved combinatorial method called the best chromosome clone plus younger generation chromosome prepotency genetic algorithm （BCC-YGCP-GA） to evaluate aquifer parameters. This method is bas...This paper developed an improved combinatorial method called the best chromosome clone plus younger generation chromosome prepotency genetic algorithm （BCC-YGCP-GA） to evaluate aquifer parameters. This method is based on a decimal simple genetic algorithm （SGA）. A synthetic example for unsteady-state flow in a two-dimensional, inhomogeneous, confined aquifer containing three hydraulically distinct zones, is used to develop data to test the model. The simulation utilizes SGA and BCC-YGCP-GA coupled to the finite element method to identify the mean zonal hydraulic conductivities, and storage coefficients of the three-compartment model. For this geometrically simple model, used as a prototype of more complex systems, the SGA does not reach convergence within 100 generations. Conversely, the convergence rate of the BCC-YGCD-GA model is very fast. The objective function value calculated by BCC-YGCD-GA is reduced to 1/1 O00th of the starting value within 100 generations, and the hydraulic conductivity and storage of three zones are within a few percent of the “true” values of the ideal model, highlighting the power of the method for aquifer parameterization.展开更多
According to traditional card problem solving which is based on the idea of genetic algorithm(GA),a set of algorithms is designed to find final solution.For each process in genetic algorithm,including choices of fitne...According to traditional card problem solving which is based on the idea of genetic algorithm(GA),a set of algorithms is designed to find final solution.For each process in genetic algorithm,including choices of fitness function,parameters determination and coding scheme selection,classic algorithm is used to realize the various steps,and ultimately to find solution of problems.展开更多
The Wayland algorithm has been improved in order to evaluate the degree of visible determinism for dynamical systems that generate time series. The objective of this study is to show that the Double-Wayland algorithm ...The Wayland algorithm has been improved in order to evaluate the degree of visible determinism for dynamical systems that generate time series. The objective of this study is to show that the Double-Wayland algorithm can distinguish between time series generated by a deterministic process and those generated by a stochastic process. The authors conducted numerical analysis of the van der Pol equation and a stochastic differential equation as a deterministic process and a Ganssian stochastic process, respectively. In case of large S/N ratios, the noise term did not affect the translation error derived from time series data, but affected that from the temporal differences of time series. In case of larger noise amplitudes, the translation error from the differences was calculated to be approximately 1 using the Double-Wayland algorithm, and it did not vary in magnitude. Furthermore, the translation error derived from the differenced sequences was considered stable against noise. This novel algorithm was applied to the detection of anomalous signals in some fields of engineering, such as the analysis of railway systems and bio-signals.展开更多
文摘For the vector attitude determination, the traditional optimal algorithms which are based on quaternion estimator（QUEST） measurement noise model are complicated for just two observations. In our application, the magnetometer and accelerometer are not two comparable kinds of sensors and both are not small field-of-view sensors as well. So in this paper a new unit measurement model is derived. According to the Wahba problem, the optimal weights for each measurement are obtained by the error variance researches. Then an improved quaternion Gauss–Newton method is presented and adopted to acquire attitude. Eventually, simulation results and experimental validation employed to test the proposed method demonstrate the usefulness of the improved algorithm.
基金supported by National Natural Science Foundation of China (Nos. U1806201, 61671261)Key Research and Development Program of Shandong Province (No. 2016GGX101007)+1 种基金China Postdoctoral Science Foundation (No. 2017T100490)University Science and Technology Planning Project of Shandong Province (Nos. J17KA058, J17KB154)
文摘At present, most underwater positioning algorithms improve the positioning accuracy by increasing the number of anchor nodes which resulting in the increasing energy consumption. To solve this problem, the paper proposes a localization algorithm assisted by mobile anchor node and based on region determination(LMRD), which not only improves the positioning accuracy of nodes positioning but also reduces the energy consumption. This algorithm is divided into two stages: region determination stage and location positioning stage. In the region determination stage, the target region is divided into several sub-regions by the region division strategy with the smallest overlap rate which can reduce the number of virtual anchor nodes and lock the target node to a sub-region, and then through the planning of mobile nodes to optimize the travel path, reduce the moving distance, and reduce system energy consumption. In the location positioning stage, the target node location can be calculated using the HILBERT path planning and trilateration. The simulation results show that the proposed algorithm can improve the positioning accuracy when the energy consumption is reduced.
文摘A new error analysis method is presented via genetic algorithms for high precise heading determination model based on two total positioning stations （TPSs）. The method has the ability to search all possible solution space by the genetic operators of elitist model and restriction. The result of analyzing the error of this model shows that the accuracy of this model is precise enough to meet the need of calibration for navigation systems on ship, and the search space is only 0. 03% of the total search space, and the precision of heading determination is 4＂ in a general dock.
基金The National Basic Research Program of China (973Program) (No2002CB312102)
文摘The underlying principle of pitch determination based on the mean shift algorithm is studied, and the cause of pitch error propagation in the original pseudo code is analyzed. The problem of error propagation is solved by choosing an appropriate initial pitch candidate F00. The theoretical choice guideline in a pitch epoch is obtained as ensuring the true pitch F0 satisfying F00/2 〈 F0 〈 3F00/2. The validity of the choice guideline is verified by the F00 experiment. Meanwhile, the algorithm is extended to the pitch determination in the noisy case and compared with the method of subharmonic-to-harmonic ratio （SHR）. The experimental results show that the improved algorithm bears comparison with SHR and it runs much faster than SHR.
基金This project was supported by the 15th Plan National Defence Science & Tehnology and Civil Space Previous Study Project.
文摘The algorithm of autonomous orbit determination for the probe around small body is studied. In the algorithm, first, the observed images of the body are compared with its pre-computed model of the body to obtain the location of the limb features of the body in the inertial coordinate. Second, the information of the images and features in utilized to obtain the position of the probe using the Levenberg-Marquardt algorithm. The position is then input to an extended Kalman filter which determines the real time orbit of the probe. Finally, considering the effective of the irregular small body shape perturbation and the small body model parameter error on the orbit determination precise, the procedure of autonomous orbit determination is validated using digital simulation.
基金supported by the Major Science and Technology Projects in Gansu Province(2023ZDGA005).
文摘This paper presents an optimization model for the location and capacity of electric vehicle(EV)charging stations.The model takes the multiple factors of the“vehicle-station-grid”system into account.Then,ArcScene is used to couple the road and power grid models and ensure that the coupling system is strictly under the goal of minimizing the total social cost,which includes the operator cost,user charging cost,and power grid loss.An immune particle swarm optimization algorithm(IPSOA)is proposed in this paper to obtain the optimal coupling strategy.The simulation results show that the algorithm has good convergence and performs well in solving multi-modal problems.It also balances the interests of users,operators,and the power grid.Compared with other schemes,the grid loss cost is reduced by 11.1%and 17.8%,and the total social cost decreases by 9.96%and 3.22%.
基金supported by the Special Fund of the Hubei Luojia Laboratory(Grant No.230100003)the Chongqing Municipal Natural Science Foundation of the General Program(Grant No.CSTB2022NSCQ-MSX1093)the Science and Technology Research Program of the Chongqing Municipal Education Commission(Grant No.KJQN202200701)。
文摘The accuracy of angles-only initial orbit determination(IOD)is significantly compromised when only a short-arc orbit is observed.The ill-conditioned problem in matrices due to weak geometric constraints caused by short arcs and observation errors typically causes significant errors in the estimated ranges and thus unsatisfactory IOD.This paper presents a critical analysis of the ill-conditioned problem using the Gooding algorithm and proposes several techniques to improve it.On the basis of multiple observations,a least-squares method is proposed to solve the ranges at the first and last epochs.For the short-arc case,the ridge estimation technique is applied to mitigate the ill-conditioned problem.To determine whether an orbit is eccentric,a procedure to assess orbit eccentricity is developed via the range-search method,which aims to provide reasonably accurate initial ranges to the Gooding algorithm.Finally,an eccentricity-constraint technique for the Gooding algorithm is proposed for cases where the orbit is determined to be nearly circular.The performances of these techniques on space-based simulation data are assessed,and an improved Gooding algorithm(I-Gooding)suitable for various observation conditions is proposed.The I-Gooding algorithm is subsequently applied to process actual ground-based observations.The results show that its accuracy in estimating the semimajor axis is 47%higher than that afforded by the standard Gooding algorithm.
基金supported by National Natural Science Foundation of China under Grant No.61172073State Key Laboratory of Networking and Switching Technology (Beijing Universityof Posts and Telecommunications) under Grant No.SKLNST-2009-1-09+1 种基金Open Research Fund of National Mobile Communications Research Laboratory, Southeast University, P. R.ChinaChina Fundamental Research Funds for the Central Universities:Beijing Jiaotong University
文摘An improved hybrid Time of Arrival (ToA)/ Angle of Arrival (AoA) location algorithm by adopting Gauss-Newton iterative algorithm is proposed. It is with the advantage of fast convergence and combining with the grid-search-based method to optimize the initial object coordinates of the iteration, meanwhile, under the condition of small measurement errors caused by noises of ToA and AoA, the algorithm performance can be improved effectively. In the Non-Line-of-Sight (NLoS) environments of the Wireless Sensor Network (WSN), simulation results show that improved accuracy is gained with moderate flexibility and fast steady convergence compared with the existing algorithms.
基金supported by Important National Science&Technology Specific Projects(No.2011ZX05021-003)
文摘Considering the situation that the least-squares(LS)method for system identification has poor robustness and the least absolute deviation(LAD)algorithm is hard to construct,an approximate least absolute deviation(ALAD)algorithm is proposed in this paper.The objective function of ALAD is constructed by introducing a deterministic function to approximate the absolute value function.Based on the function,the recursive equations for parameter identification are derived using Gauss-Newton iterative algorithm without any simplification.This algorithm has advantages of simple calculation and easy implementation,and it has second order convergence speed.Compared with the LS method,the new algorithm has better robustness when disorder and peak noises exist in the measured data.Simulation results show the efficiency of the proposed method.
文摘Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of 2021.Considering that Turkey announced the Turkish Lira Overnight Reference Interest Rate(TLREF),this study examines the determinants of TLREF.In this context,three global determinants,five country-level macroeconomic determinants,and the COVID-19 pandemic are considered by using daily data between December 28,2018,and December 31,2020,by performing machine learning algorithms and Ordinary Least Square.The empirical results show that(1)the most significant determinant is the amount of securities bought by Central Banks;(2)country-level macroeconomic factors have a higher impact whereas global factors are less important,and the pandemic does not have a significant effect;(3)Random Forest is the most accurate prediction model.Taking action by considering the study’s findings can help support economic growth by achieving low-level benchmark rates.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.32371280 and T2350011)。
文摘Considering the pivotal role of single-wavelength anomalous diffraction(SAD) in macromolecular crystallography,our objective was to introduce DSAS,a novel program designed for efficient anomalous scattering substructure determination.DSAS stands out with its core components:a modified phase-retrieval algorithm and automated parameter tuning.The software boasts an intuitive graphical user interface(GUI),facilitating seamless input of essential data and real-time monitoring.Extensive testing on DSAS has involved diverse datasets,encompassing proteins,nucleic acids,and various anomalous scatters such as sulfur(S),selenium(Se),metals,and halogens.The results confirm DSAS’s exceptional performance in accurately determining heavy atom positions,making it a highly effective tool in the field.
文摘This paper developed an improved combinatorial method called the best chromosome clone plus younger generation chromosome prepotency genetic algorithm （BCC-YGCP-GA） to evaluate aquifer parameters. This method is based on a decimal simple genetic algorithm （SGA）. A synthetic example for unsteady-state flow in a two-dimensional, inhomogeneous, confined aquifer containing three hydraulically distinct zones, is used to develop data to test the model. The simulation utilizes SGA and BCC-YGCP-GA coupled to the finite element method to identify the mean zonal hydraulic conductivities, and storage coefficients of the three-compartment model. For this geometrically simple model, used as a prototype of more complex systems, the SGA does not reach convergence within 100 generations. Conversely, the convergence rate of the BCC-YGCD-GA model is very fast. The objective function value calculated by BCC-YGCD-GA is reduced to 1/1 O00th of the starting value within 100 generations, and the hydraulic conductivity and storage of three zones are within a few percent of the “true” values of the ideal model, highlighting the power of the method for aquifer parameterization.
文摘According to traditional card problem solving which is based on the idea of genetic algorithm(GA),a set of algorithms is designed to find final solution.For each process in genetic algorithm,including choices of fitness function,parameters determination and coding scheme selection,classic algorithm is used to realize the various steps,and ultimately to find solution of problems.
文摘The Wayland algorithm has been improved in order to evaluate the degree of visible determinism for dynamical systems that generate time series. The objective of this study is to show that the Double-Wayland algorithm can distinguish between time series generated by a deterministic process and those generated by a stochastic process. The authors conducted numerical analysis of the van der Pol equation and a stochastic differential equation as a deterministic process and a Ganssian stochastic process, respectively. In case of large S/N ratios, the noise term did not affect the translation error derived from time series data, but affected that from the temporal differences of time series. In case of larger noise amplitudes, the translation error from the differences was calculated to be approximately 1 using the Double-Wayland algorithm, and it did not vary in magnitude. Furthermore, the translation error derived from the differenced sequences was considered stable against noise. This novel algorithm was applied to the detection of anomalous signals in some fields of engineering, such as the analysis of railway systems and bio-signals.
