An optical inspection method of the Ball Grid Array package(BGA) was proposed by using a machine vision system. The developed machine vision system could get main critical factors for BGA quality evaluation, such as t...An optical inspection method of the Ball Grid Array package(BGA) was proposed by using a machine vision system. The developed machine vision system could get main critical factors for BGA quality evaluation, such as the height of solder ball, diameter, pitch and coplanarity. The experiment has proved that this system is available for BGA failure detection.展开更多
Assessing machine's performance through comparing the same or similar machines is important to implement intelligent maintenance for swarm machine.In this paper,an outlier mining based abnormal machine detection a...Assessing machine's performance through comparing the same or similar machines is important to implement intelligent maintenance for swarm machine.In this paper,an outlier mining based abnormal machine detection algorithm is proposed for this purpose.Firstly,the outlier mining based on clustering is introduced and the definition of cluster-based global outlier factor(CBGOF) is presented.Then the modified swarm intelligence clustering(MSIC) algorithm is suggested and the outlier mining algorithm based on MSIC is proposed.The algorithm can not only cluster machines according to their performance but also detect possible abnormal machines.Finally,a comparison of mobile soccer robots' performance proves the algorithm is feasible and effective.展开更多
A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells using both quadratic and cubic basis functions.By analyzing the discrete isogeometric equati...A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells using both quadratic and cubic basis functions.By analyzing the discrete isogeometric equations with the aid of harmonic wave assumption,the frequency error measures are rationally derived for the quadratic and cubic formulations for Kirchhoff–Love cylindrical shells.In particular,the governing relationship of the continuum frequency for Kirchhoff–Love cylindrical shells is naturally embedded into the frequency error measures without the need of explicit frequency expressions,which usually are not trivial for the shell problems.In accordance with these theoretical findings,the 2nd and 4th orders of frequency accuracy are attained for the isogeometric schemes using quadratic and cubic basis functions,respectively.Numerical results not only thoroughly verify the theoretical convergence rates of frequency solutions,but also manifest an excellent magnitude match between numerical and theoretical frequency errors for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells.展开更多
Accurate battery capacity prediction is important to ensure reliable battery operation and reduce the cost.However,the complex nature of battery degradation and the presence of capacity regeneration phenomenon render ...Accurate battery capacity prediction is important to ensure reliable battery operation and reduce the cost.However,the complex nature of battery degradation and the presence of capacity regeneration phenomenon render the prediction task very challenging.To address this problem,this paper proposes a novel and efficient algorithm to predict the battery capacity trajectory in a multi-cell setting.The proposed method is a new variant of Gaussian process regression(GPR)model,and it utilizes similar trajectories in the historical data to enhance the prediction of desired capacity trajectory.More importantly,the proposed method adds no extra computation cost to the standard GPR.To demonstrate the effectiveness of the proposed method,validation tests on two different battery datasets are implemented in the case studies.The prediction results and the computation cost are carefully benchmarked with cuttingedge GPR approaches for battery capacity prediction.展开更多
文摘An optical inspection method of the Ball Grid Array package(BGA) was proposed by using a machine vision system. The developed machine vision system could get main critical factors for BGA quality evaluation, such as the height of solder ball, diameter, pitch and coplanarity. The experiment has proved that this system is available for BGA failure detection.
基金the National Natural Science Foundation of China (No. 50705054)
文摘Assessing machine's performance through comparing the same or similar machines is important to implement intelligent maintenance for swarm machine.In this paper,an outlier mining based abnormal machine detection algorithm is proposed for this purpose.Firstly,the outlier mining based on clustering is introduced and the definition of cluster-based global outlier factor(CBGOF) is presented.Then the modified swarm intelligence clustering(MSIC) algorithm is suggested and the outlier mining algorithm based on MSIC is proposed.The algorithm can not only cluster machines according to their performance but also detect possible abnormal machines.Finally,a comparison of mobile soccer robots' performance proves the algorithm is feasible and effective.
基金support of this work by the National Natural Science Foundation of China(Grant Nos.12072302,11772280)the Natural Science Foundation of Fujian Province of China(No.2021J02003)is gratefully acknowledged.
文摘A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells using both quadratic and cubic basis functions.By analyzing the discrete isogeometric equations with the aid of harmonic wave assumption,the frequency error measures are rationally derived for the quadratic and cubic formulations for Kirchhoff–Love cylindrical shells.In particular,the governing relationship of the continuum frequency for Kirchhoff–Love cylindrical shells is naturally embedded into the frequency error measures without the need of explicit frequency expressions,which usually are not trivial for the shell problems.In accordance with these theoretical findings,the 2nd and 4th orders of frequency accuracy are attained for the isogeometric schemes using quadratic and cubic basis functions,respectively.Numerical results not only thoroughly verify the theoretical convergence rates of frequency solutions,but also manifest an excellent magnitude match between numerical and theoretical frequency errors for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells.
文摘Accurate battery capacity prediction is important to ensure reliable battery operation and reduce the cost.However,the complex nature of battery degradation and the presence of capacity regeneration phenomenon render the prediction task very challenging.To address this problem,this paper proposes a novel and efficient algorithm to predict the battery capacity trajectory in a multi-cell setting.The proposed method is a new variant of Gaussian process regression(GPR)model,and it utilizes similar trajectories in the historical data to enhance the prediction of desired capacity trajectory.More importantly,the proposed method adds no extra computation cost to the standard GPR.To demonstrate the effectiveness of the proposed method,validation tests on two different battery datasets are implemented in the case studies.The prediction results and the computation cost are carefully benchmarked with cuttingedge GPR approaches for battery capacity prediction.
